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1. Quantum thermometry with single molecules in portable nanoprobes

Author

Esteso, V., Duquennoy, R., Ng, R. C., Colautti, M., Lombardi, P., Arregui, G., Chavez-Ángel, E., Sotomayor-Torres, C. M., García, P. D., Hilke, M., and Toninelli, C.

Subjects
Physics - Applied Physics, Quantum Physics
Abstract

Understanding heat transport is relevant to develop efficient strategies for thermal management in microelectronics for instance, as well as for fundamental science purposes. However, measuring temperatures in nanostructured environments and in cryogenic conditions remains a challenging task, that requires both high sentitivity and a non-invasive approach. Here we present a portable nanothermometer based on a molecular two-level quantum system that operates in the 3 - 30 K temperature range, with excellent temperature and spatial resolutions on the order of mK and $\mu$m, respectively. We validate the performance of this molecular thermometer on nanostructures, by estimating the thermal conductivity of a patterned silicon membrane. In addition, we demonstrate the two-dimensional temperature mapping of a patterned surface via the simultaneous spectroscopy of all thermometers deposited on a sample. These results demonstrate the potential of this molecular thermometer to explore thermal properties and related phenomena at cryogenic temperatures., Comment: 12 pages, 6 figures

Published
2023

2. Engineering nanoscale hypersonic phonon transport

Author

Florez, O., Arregui, G., Albrechtsen, M., Ng, R. C., Gomis-Bresco, J., Stobbe, S., Sotomayor-Torres, C. M., and García, P. D.

Subjects
Physics - Optics, Quantum Physics
Abstract

Controlling the vibrations in solids is crucial to tailor their mechanical properties and their interaction with light. Thermal vibrations represent a source of noise and dephasing for many physical processes at the quantum level. One strategy to avoid these vibrations is to structure a solid such that it possesses a phononic stop band, i.e., a frequency range over which there are no available mechanical modes. Here, we demonstrate the complete absence of mechanical vibrations at room temperature over a broad spectral window, with a 5.3 GHz wide band gap centered at 8.4 GHz in a patterned silicon nanostructure membrane measured using Brillouin light scattering spectroscopy. By constructing a line-defect waveguide, we directly measure GHz localized modes at room temperature. Our experimental results of thermally excited guided mechanical modes at GHz frequencies provides an eficient platform for photon-phonon integration with applications in optomechanics and signal processing transduction.

Published
2022
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3. Room-temperature silicon platform for GHz-frequency nano-electro-opto-mechanical systems

Author

Navarro-Urrios, D., Colombano, M. F., Arregui, G., Madiot, G., Pitanti, A., Griol, A., Makkonen, T., Ahopelto, J., Sotomayor-Torres, C. M., and Martínez, A.

Subjects
Physics - Optics, Physics - Applied Physics
Abstract

Nano-electro-opto-mechanical systems enable the synergistic coexistence of electrical, mechanical, and optical signals on a chip to realize new functions. Most of the technology platforms proposed for the fabrication of these systems so far are not fully compatible with the mainstream CMOS technology, thus hindering mass-scale utilization. We have developed a CMOS technology platform for nano-electro-opto-mechanical systems that includes piezoelectric interdigitated transducers for electronic driving of mechanical signals and nanocrystalline silicon nanobeams for enhanced optomechanical interaction. Room temperature operation of devices at 2 GHz and with peak sensitivity down to 2.6 cavity phonons is demonstrated. Our proof-of-principle technology platform can be integrated and interfaced with silicon photonics, electronics, and MEMS devices and may enable multiple functions for coherent signal processing in the classical and quantum domains., Comment: 10 pages, 3 figures. Comments are welcome

Published
2021

4. Optomechanical crystals for spatial sensing of submicron sized analytes

Author

Navarro-Urrios, D., Kang, E., Xiao, P., Colombano, M. F., Arregui, G., Graczykowski, B., Capuj, N. E., Sledzinska, M., Sotomayor-Torres, C. M., and Fytas, G.

Subjects
Physics - Optics, Physics - Applied Physics
Abstract

Optomechanical crystal cavities have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, bacteria and viruses. In this work we demonstrate the working principle of an optomechanical crystal cavity operating under ambient conditions as a sensor of submicrometer analytes by optically monitoring the frequency shift of thermally activated mechanical modes. The resonator has been specifically designed so that the cavity region supports a particular family of low modal-volume mechanical modes, commonly known as -pinch modes-. These involve the oscillation of only a couple of adjacent cavity cells that are relatively insensitive to perturbations in other parts of the resonator. The eigenfrequency of these modes decreases as the deformation is localized closer to the centre of the resonator. Thus, by identifying specific modes that undergo a frequency shift that amply exceeds the mechanical linewidth, it is possible to infer if there are particles deposited on the resonator, how many are there and their approximate position within the cavity region., Comment: 15 pages, 3 figures, Supplementary Info (10 pages, 9 figures)

Published
2020
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5. Ferromagnetic resonance assisted optomechanical magnetometer

Author

Colombano, M. F., Arregui, G., Bonell, F., Capuj, N. E., Chavez-Angel, E., Pitanti, A., Valenzuela, S. O., Sotomayor-Torres, C. M., Navarro-Urrios, D., and Costache, M. V.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Applied Physics, Physics - Optics
Abstract

The resonant enhancement of mechanical and optical interaction in optomechanical cavities enables their use as extremely sensitive displacement and force detectors. In this work we demonstrate a hybrid magnetometer that exploits the coupling between the resonant excitation of spin waves in a ferromagnetic insulator and the resonant excitation of the breathing mechanical modes of a glass microsphere deposited on top. The interaction is mediated by magnetostriction in the ferromagnetic material and the consequent mechanical driving of the microsphere. The magnetometer response thus relies on the spectral overlap between the ferromagnetic resonance and the mechanical modes of the sphere, leading to a peak sensitivity better than 900 pT Hz$^{-1/2}$ at 206 MHz when the overlap is maximized. By externally tuning the ferromagnetic resonance frequency with a static magnetic field we demonstrate sensitivity values at resonance around a few nT Hz$^{-1/2}$ up to the GHz range. Our results show that our hybrid system can be used to build high-speed sensor of oscillating magnetic fields.

Published
2019
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6. Coherent generation and detection of acoustic phonons in topological nanocavities

Author

Arregui, G., Ortíz, O., Esmann, M., Sotomayor-Torres, C. M., Gomez-Carbonell, C., Mauguin, O., Perrin, B., Lemaître, A., García, P. D., and Lanzillotti-Kimura, N. D.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science, Physics - Optics
Abstract

Inspired by concepts developed for fermionic systems in the framework of condensed matter physics, topology and topological states are recently being explored also in bosonic systems. The possibility of engineering systems with unidirectional wave propagation and protected against disorder is at the heart of this growing interest. Topogical acoustic effects have been observed in a variety of systems, most of them based on kHz-MHz sound waves, with typical wavelength of the order of the centimeter. Recently, some of these concepts have been successfully transferred to acoustic phonons in nanoscaled multilayered systems. The reported demonstration of confined topological phononic modes was based on Raman scattering spectroscopy, yet the resolution did not suffice to determine lifetimes and to identify other acoustic modes in the system. Here, we use time-resolved pump-probe measurements using an asynchronous optical sampling (ASOPS) technique to overcome these resolution limitations. By means of one-dimensional GaAs/AlAs distributed Bragg reflectors (DBRs) as building blocks, we engineer high frequency ($\sim$ 200 GHz) topological acoustic interface states. We are able to clearly distinguish confined topological states from stationary band edge modes. The detection scheme reflects the symmetry of the modes directly through the selection rules, evidencing the topological nature of the measured confined state. These experiments enable a new tool in the study of the more complex topology-driven phonon dynamics such as phonon nonlinearities and optomechanical systems with simultaneous confinement of light and sound., Comment: 6 pages, 3 figures

Published
2018
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7. Synchronization of optomechanical cavities by mechanical interaction

Author

Colombano, M. F., Arregui, G., Capuj, N. E., Pitanti, A., Maire, J., Griol, A., Garrido, B., Martinez, A., Sotomayor-Torres, C. M., and Navarro-Urrios, D.

Subjects
Physics - Optics
Abstract

The synchronization of coupled oscillators is a phenomenon found throughout nature. Mechanical oscillators are paradigmatic among such systems, but realising them at the nanoscale is challenging. We report synchronization of the mechanical dynamics of a pair of optomechanical crystal cavities that are intercoupled with a mechanical link and support independent optical modes. In this regime they oscillate in anti-phase, which is in agreement with the predictions of our numerical model that considers reactive coupling. Finally, we show how to temporarily disable synchronization of the coupled system by actuating one of the cavities with a heating laser, so that both cavities oscillate independently. Our results can be upscaled to more than two cavities and are thus the first step towards realizing integrated networks of synchronized optomechanical oscillators. Such networks promise unparalleled performances for time-keeping and sensing purposes and unveil a new route for neuromorphic computing applications., Comment: 13 pages, 5 figures. Supplementary material: 11 pages, 7 figures

Published
2018
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8. Impact of the regularization parameter in the Mean Free Path reconstruction method: Nanoscale heat transport and beyond

Author

Sánchez-Martínez, M. -A., Alzina, F., Oyarzo, J., Sotomayor-Torres, C. M., and Chavez-Angel, E.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

The understanding of the mean free path (MFP) distribution of the energy carriers in materials (e.g. electrons, phonons, magnons, etc.) is a key physical insight into their transport properties. In this context, MFP spectroscopy has become an important tool to describe the contribution of carriers with different MFP to the total transport phenomenon. In this work, we revise the MFP reconstruction technique and present a study on the impact of the regularization parameter on the MFP distribution of the energy carriers. By using the L-curve criterion, we calculate the optimal mathematical value of the regularization parameter. The effect of the change from the optimal value in the MFP distribution is analyzed in three case studies of heat transport by phonons. These results demonstrate that the choice of the regularization parameter has a large impact on the physical information obtained from the reconstructed accumulation function, and thus cannot be chosen arbitrarily. The approach can be applied to various transport phenomena at the nanoscale involving carriers of different physical nature and behavior.

Published
2018
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9. Unveiled electric profiles within hydrogen bonds suggest DNA base pairs with similar bond strengths

Author

Ruiz-Blanco, Y. B., Almeida, Y., Sotomayor-Torres, C. M., and García, Y.

Subjects
Quantitative Biology - Biomolecules, Physics - Biological Physics
Abstract

Electrical forces are the background of all the interactions occurring in biochemical systems. From here and by using a combination of ab-initio and ad-hoc models, we introduce the first description of electric field profiles with intrabond resolution to support a characterization of single bond forces attending to its electrical origin. This fundamental issue has eluded a physical description so far. Our method is applied to describe hydrogen bonds (HB) in DNA base pairs. Numerical results reveal that base pairs in DNA could be equivalent considering HB strength contributions, which challenges previous interpretations of thermodynamic properties of DNA based on the assumption that Adenine/Thymine pairs are weaker than Guanine/Cytosine pairs due to the sole difference in the number of HB. Thus, our methodology provides solid foundations to support the development of extended models intended to go deeper into the molecular mechanisms of DNA functioning., Comment: Full version is available on: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0185638

Published
2018
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10. Optical modulation of coherent phonon emission in optomechanical cavities

Author

Maire, J., Capuj, N. E., Colombano, M. F., Griol, A., Martinez, A., Sotomayor-Torres, C. M., and Navarro-Urrios, D.

Subjects
Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Optomechanical structures are well suited to study photon-phonon interactions, and they also turn out to be potential building blocks for phononic circuits and quantum computing. In phononic circuits, in which information is carried and processed by phonons, optomechanical structures could be used as interfaces to photons and electrons thanks to their excellent coupling efficiency. Among the components required for phononic circuits, such structures could be used to create coherent phonon sources and detectors. Complex functions other than emission or detection remain challenging and addressing a single structure in a full network proves a formidable challenge. Here, we propose and demonstrate a way to modulate the coherent emission from optomechanical crystals by external optical pumping, effectively creating a phonon switch working at ambient conditions of pressure and temperature and the working speed of which (5 MHz) is only limited by the mechanical motion of the optomechanical structure. We additionally demonstrate two other switching schemes: harmonic switching in which the mechanical mode remains active but different harmonics of the optical force are used, and switching to- and from the chaotic regime. Furthermore, the method presented here allows to select any single structure without affecting its surroundings, which is an important step towards freely controllable networks of optomechanical phonon emitters., Comment: 11 pages, 5 figures

Published
2018
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11. Nanocrystalline silicon optomechanical cavities

Author

Navarro-Urrios, D., Capuj, N. E., Maire, J., Colombano, M., Jaramillo-Fernandez, J., Chavez-Angel, E., Martin, L. L., Mercade, L., Griol, A., Martinez, A., Sotomayor-Torres, C. M., and Ahopelto, J.

Subjects
Physics - Optics
Abstract

Silicon on insulator photonics has offered a versatile platform for the recent development of integrated optomechanical circuits. However, there are some constraints such as the high cost of the wafers and limitation to a single physical device level. In the present work we investigate nanocrystalline silicon as an alternative material for optomechanical devices. In particular, we demonstrate that optomechanical crystal cavities fabricated of nanocrystalline silicon have optical and mechanical properties enabling non-linear dynamical behaviour and effects such as thermo-optic/free-carrier-dispersion self-pulsing, phonon lasing and chaos, all at low input laser power and with typical frequencies as high as 0.3 GHz., Comment: 16 pages, 6 figures

Published
2018
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12. Mechanical oscillations in lasing microspheres

Author

Toncelli, A., Capuj, N. E., Garrido, B., Sledzinska, M., Sotomayor-Torres, C. M., Tredicucci, A., and Navarro-Urrios, D.

Subjects
Physics - Optics
Abstract

We investigate the feasibility of activating coherent mechanical oscillations in lasing microspheres by modulating the laser emission at a mechanical eigenfrequency. To this aim, 1.5% Nd3+:Barium-Titanium-Silicate microspheres with diameters around 50 {\mu}m were used as high quality factor (Q>10^6) whispering gallery mode lasing cavities. We have implemented a pump-and-probe technique in which the pump laser used to excite the Nd3+ ions is focused on a single microsphere with a microscope objective and a probe laser excites a specific optical mode with the evanescent field of a tapered fibre. The studied microspheres show monomode and multi-mode lasing action, which can be modulated in the best case up to 10 MHz. We have optically transduced thermally-activated mechanical eigenmodes appearing in the 50-70 MHz range, the frequency of which decreases with increasing the size of the microspheres. In a pump-and-probe configuration we observed modulation of the probe signal up to the maximum pump modulation frequency of our experimental setup, i.e., 20 MHz. This modulation decreases with frequency and is unrelated to lasing emission, pump scattering or thermal effects. We associate this effect to free-carrier-dispersion induced by multiphoton pump light absorption. On the other hand, we conclude that, in our current experimental conditions, it was not possible to resonantly excite the mechanical modes. Finally, we discuss on how to overcome these limitations by increasing the modulation frequency of the lasing emission and decreasing the frequency of the mechanical eigenmodes displaying a strong degree of optomechanical coupling., Comment: 17 pages, 5 figures

Published
2017
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13. Orthotropic Piezoelectricity in 2D Nanocellulose

Author

García, Y., Ruiz-Blanco, Yasser B., Marrero-Ponce, Yovani, and Sotomayor-Torres, C. M.

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Other Condensed Matter, Physics - Applied Physics, Physics - Atomic and Molecular Clusters
Abstract

The control of electromechanical responses within bonding regions is essential to face frontier challenges in nanotechnologies, such as molecular electronics and biotechnology. Here, we present I\b{eta}-nanocellulose as a potentially new orthotropic 2D piezoelectric crystal. The predicted in-layer piezoelectricity is originated on a sui-generis hydrogen bonds pattern. Upon this fact and by using a combination of ab-initio and ad-hoc models, we introduce a description of electrical profiles along chemical bonds. Such developments lead to obtain a rationale for modelling the extended piezoelectric effect originated within bond scales. The order of magnitude estimated for the 2D I\b{eta}-nanocellulose piezoelectric response, ~pm V-1, ranks this material at the level of currently used piezoelectric energy generators and new artificial 2D designs. Such finding would be crucial for developing alternative materials to drive emerging nanotechnologies., Comment: 5 figures included. Supp. Mat. available on the online version: https://www.nature.com/articles/srep34616, Others on: http://www.nanowerk.com/nanotechnology-news/newsid=44806.php

Published
2017
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15. Nonlinear dynamics and chaos in an optomechanical beam

Author

Navarro-Urrios, D., Capuj, N. E., Colombano, M. F., Garcia, P. D., Sledzinska, M., Alzina, F., Griol, A., Martinez, A., and Sotomayor-Torres, C. M.

Subjects
Physics - Optics
Abstract

Optical non-linearities, such as thermo-optic effects and free-carrier-dispersion, are often considered as undesired effects in silicon-based resonators and, more specifically, optomechanical (OM) cavities, affecting the relative detuning between an optical resonance and the excitation laser. However, the interplay between such mechanisms could also enable unexpected physical phenomena to be used in new applications. In the present work, we exploit those non-linearities and their intercoupling with the mechanical degrees of freedom of a silicon OM nanobeam to unveil a rich set of fundamentally different complex dynamics. By smoothly changing the parameters of the excitation laser, namely its power and wavelength, we demonstrate accurate control for activating bi-dimensional and tetra-dimensional limit-cycles, a period doubling route and chaos. In addition, by scanning the laser parameters in opposite senses we demonstrate bistability and hysteresis between bi-dimensional and tetra-dimensional limit-cycles, between different coherent mechanical states and between tetra-dimensional limit-cycles and chaos. As a result of implementing the Rosenstein algorithm to the experimental time series we have extracted a Largest Lyapunov Exponent of LLE=1.3x10^5 s-1, which is between one and two orders of magnitude lower than the typical oscillating frequencies of the system. Most of the experimental features can be well reproduced with a model of first-order non-linear differential equations coupled through the number of intracavity photons. Our findings open several routes towards exploiting silicon-based OM photonic crystals for systems with memory and, more specifically, for chaos based applications such as secure information transfer or sensing., Comment: Main file:12 pages, 5 figures Supplementary Information: 15 pages, 14 figures

Published
2016
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16. Optical and mechanical mode tuning in an optomechanical crystal with light-induced thermal effects

Author

Navarro-Urrios, D., Gomis-Bresco, J., Capuj, N. E., Alzina, F., Griol, A., Puerto, D., Martínez, A., and Sotomayor-Torres, C. M.

Subjects
Physics - Optics
Abstract

We report on the modification of the optical and mechanical properties of a silicon 1D optomechanical crystal cavity due to thermo-optic effects in a high phonon/photon population regime. The cavity heats up due to light absorption in a way that shifts the optical modes towards longer wavelengths and the mechanical modes to lower frequencies. By combining the experimental optical results with finite-difference time-domain simulations we establish a direct relation between the observed wavelength drift and the actual effective temperature increase of the cavity. By assuming that the Young's modulus decreases accordingly to the temperature increase, we find a good agreement between the mechanical mode drift predicted using a finite element method and the experimental one., Comment: 16 pages, 5 figures

Published
2016
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17. In situ Raman analysis of reduced-graphene oxide-based electroactive nanofluids

Author

Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, European Research Council, Parpal, Monica, El Sachat, Alexandros, Sotomayor Torres, C. M., Gómez-Romero, P., Rueda-García, Daniel, Chávez-Angel, Emigdio, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, European Research Council, Parpal, Monica, El Sachat, Alexandros, Sotomayor Torres, C. M., Gómez-Romero, P., Rueda-García, Daniel, and Chávez-Angel, Emigdio

Abstract

This study investigates the effect of an applied stationary voltage on the vibrational properties of 1 M H2SO4 and H2SO4-based reduced-graphene oxide (rGO) nanofluids, commonly used as electrolytes in electrochemical cells. Our findings indicate that the energy of the symmetric stretching vibrations of H2SO4 remains unaffected by the electric field. However, a slight deviation toward lower energy and an enhancement of Raman intensity are observed in the asymmetric stretching vibration of H2SO4 due to the applied voltage. Furthermore, the addition of rGO to the base fluid produces a significant redshift in the symmetric stretching bands, indicating that the presence of rGO produces important changes at the macroscopic level in the base fluid. Synchronous and asynchronous maps further uncover the positive correlations between the D and G bands as well as between rGO and the base fluid bands. Specifically, the asynchronous map revealed complex dynamics between the rGO and H2SO4 bands and only positive correlations between H2SO4 bands. These results demonstrate the potential of Raman spectroscopy as a non-invasive technique to systematically study the influence of electric fields on the vibrational properties of fluids and nanofluids, which can ultimately lead to the development of significantly more efficient electrochemical cells.

Published
2024

19. Intermodulation of optical frequency combs in a multimode optomechanical system

Author

European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, Villum Fonden, Danish National Research Foundation, Innovation Fund Denmark, Independent Research Fund Denmark, Ng, Ryan C. [0000-0002-0527-9130], Navarro-Urrios, D. [0000-0001-9055-1583], Arregui, Guillermo [0000-0002-6458-5277], Albrechtsen, Marcus [0000-0003-4226-0997], García, Pedro David [0000-0002-3422-178X], Stobbe, Søren [0000-0002-0991-041X], Sotomayor Torres, C. M. [0000-0001-9986-2716], Madiot, Guilhem [0000-0003-2662-4324], Ng, Ryan C., Nizet, Paul, Navarro-Urrios, D., Arregui, Guillermo, Albrechtsen, Marcus, García, Pedro David, Stobbe, Søren, Sotomayor Torres, C. M., Madiot, Guilhem, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, Villum Fonden, Danish National Research Foundation, Innovation Fund Denmark, Independent Research Fund Denmark, Ng, Ryan C. [0000-0002-0527-9130], Navarro-Urrios, D. [0000-0001-9055-1583], Arregui, Guillermo [0000-0002-6458-5277], Albrechtsen, Marcus [0000-0003-4226-0997], García, Pedro David [0000-0002-3422-178X], Stobbe, Søren [0000-0002-0991-041X], Sotomayor Torres, C. M. [0000-0001-9986-2716], Madiot, Guilhem [0000-0003-2662-4324], Ng, Ryan C., Nizet, Paul, Navarro-Urrios, D., Arregui, Guillermo, Albrechtsen, Marcus, García, Pedro David, Stobbe, Søren, Sotomayor Torres, C. M., and Madiot, Guilhem

Abstract

Phonons offer the possibility to connect the microwave and optical domains while being efficiently transduced with electronic and optical signals. Here, we present a multimodal optomechanical platform, consisting of a mechanical-optical-mechanical resonator configuration. The mechanical modes, with frequencies at 265 MHz and 6.8 GHz, can be simultaneously excited into a phonon lasing regime as supported by a stability analysis of the system. Both the megahertz and gigahertz modes enter a self-sustained oscillation regime, leading to the intermodulation of two frequency combs in the optical field. We characterize this platform experimentally, demonstrating previously unexplored dynamical regimes. These results suggest the possibility to control multiple mechanical degrees of freedom via a single optical mode, with implications in gigahertz phononic devices, signal processing, and optical comb sensing applications.

Published
2023

20. Improved High Temperature Thermoelectric Properties in Misfit Ca3Co4O9 by Thermal Annealing

Author

Ministerio de Economía y Competitividad (España), Centre National de la Recherche Scientifique (France), Consejo Superior de Investigaciones Científicas (España), European Commission, Generalitat de Catalunya, Comisión Asesora de Investigación Científica y Técnica, CAICYT (España), Sachat, Alexandros el [0000-0003-3798-9724], Castro-Álvarez, Alejandro [0000-0001-8360-8027], Sotomayor Torres, C. M. [0000-0001-9986-2716], Chávez-Angel, Emigdio [0000-0002-9783-0806], Chatterjee, Arindom, Sachat, Alexandros el, Banik, Ananya, Biswas, Kanishka, Castro-Álvarez, Alejandro, Sotomayor Torres, C. M., Santiso, José, Chávez-Angel, Emigdio, Ministerio de Economía y Competitividad (España), Centre National de la Recherche Scientifique (France), Consejo Superior de Investigaciones Científicas (España), European Commission, Generalitat de Catalunya, Comisión Asesora de Investigación Científica y Técnica, CAICYT (España), Sachat, Alexandros el [0000-0003-3798-9724], Castro-Álvarez, Alejandro [0000-0001-8360-8027], Sotomayor Torres, C. M. [0000-0001-9986-2716], Chávez-Angel, Emigdio [0000-0002-9783-0806], Chatterjee, Arindom, Sachat, Alexandros el, Banik, Ananya, Biswas, Kanishka, Castro-Álvarez, Alejandro, Sotomayor Torres, C. M., Santiso, José, and Chávez-Angel, Emigdio

Abstract

Ca3Co4O9, a p-type thermoelectric material based on transition-metal oxides, has garnered significant interest due to its potential in thermoelectric applications. Its unique misfit-layered crystal structure contributes to low thermal conductivity and a high Seebeck coefficient, leading to a thermoelectric figure of merit (zT) of ≥1 at 1000 K. Conventionally, it has been believed that thermopower reaches its upper limit above 200 K. However, our thermopower measurements on polycrystalline Ca3Co4O9 samples have revealed an unexpected increase in thermopower above 380 K. In this study, we investigate the effects of high oxygen pressure annealing on Ca3Co4O9 and provide an explanation based on the mixed oxide states of cobalt and carrier hopping. Our results demonstrate that annealing induces modifications in the defect chemistry of Ca3Co4O9, leading to a decrease in electron hopping probability and the emergence of a thermal activation-like behavior in thermopower. These findings carry significant implications for the design and optimization of thermoelectric materials based on misfit cobaltates, opening new avenues for enhanced thermoelectric performance.

Published
2023

21. Optomechanical Generation of Coherent GHz Vibrations in a Phononic Waveguide

Author

European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Villum Fonden, Danish National Research Foundation, Innovation Fund Denmark, Independent Research Fund Denmark, Madiot, Guilhem [0000-0003-2662-4324], Ng, Ryan C. [0000-0002-0527-9130], Arregui, Guillermo [0000-0002-6458-5277], Florez, Omar [0000-0001-6662-9811], Albrechtsen, Marcus [0000-0003-4226-0997], Sotomayor Torres, C. M. [0000-0001-9986-2716], Madiot, Guilhem, Ng, Ryan C., Arregui, Guillermo, Florez, Omar, Albrechtsen, Marcus, Stobbe, Søren, García, Pedro David, Sotomayor Torres, C. M., European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Villum Fonden, Danish National Research Foundation, Innovation Fund Denmark, Independent Research Fund Denmark, Madiot, Guilhem [0000-0003-2662-4324], Ng, Ryan C. [0000-0002-0527-9130], Arregui, Guillermo [0000-0002-6458-5277], Florez, Omar [0000-0001-6662-9811], Albrechtsen, Marcus [0000-0003-4226-0997], Sotomayor Torres, C. M. [0000-0001-9986-2716], Madiot, Guilhem, Ng, Ryan C., Arregui, Guillermo, Florez, Omar, Albrechtsen, Marcus, Stobbe, Søren, García, Pedro David, and Sotomayor Torres, C. M.

Abstract

Nanophononics has the potential for information transfer, in an analogous manner to its photonic and electronic counterparts. The adoption of phononic systems has been limited, due to difficulties associated with the generation, manipulation, and detection of phonons, especially at GHz frequencies. Existing techniques often require piezoelectric materials with an external radiofrequency excitation that are not readily integrated into existing CMOS infrastructures, while nonpiezoelectric demonstrations have been inefficient. In this Letter, we explore the optomechanical generation of coherent phonons in a suspended 2D silicon phononic crystal cavity with a guided mode around 6.8 GHz. By incorporating an air-slot into this cavity, we turn the phononic waveguide into an optomechanical platform that exploits localized photonic modes resulting from inherent fabrication imperfections for the transduction of mechanics. Such a platform exhibits very fine control of phonons using light, and is capable of coherent self-sustained phonon generation around 6.8 GHz, operating at room temperature. The ability to generate high frequency coherent mechanical vibrations within such a simple 2D CMOS-compatible system could be a first step towards the development of sources in phononic circuitry and the coherent manipulation of other solid-state properties.

Published
2023

22. Enhanced Thermoelectric Properties of Misfit Bi2Sr2-xCaxCo2Oy: Isovalent Substitutions and Selective Phonon Scattering

Author

Ministerio de Economía y Competitividad (España), Centre National de la Recherche Scientifique (France), Consejo Superior de Investigaciones Científicas (España), Generalitat de Catalunya, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Sachat, Alexandros el [0000-0003-3798-9724], Padilla-Pantoja, Jessica [0000-0002-7769-7753], Sotomayor Torres, C. M. [0000-0001-9986-2716], Chávez-Angel, Emigdio [0000-0002-9783-0806], Chatterjee, Arindom, Banik, Ananya, Sachat, Alexandros el, Caicedo, José Manuel, Padilla-Pantoja, Jessica, Sotomayor Torres, C. M., Biswas, Kanishka, Santiso, José, Chávez-Angel, Emigdio, Ministerio de Economía y Competitividad (España), Centre National de la Recherche Scientifique (France), Consejo Superior de Investigaciones Científicas (España), Generalitat de Catalunya, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Sachat, Alexandros el [0000-0003-3798-9724], Padilla-Pantoja, Jessica [0000-0002-7769-7753], Sotomayor Torres, C. M. [0000-0001-9986-2716], Chávez-Angel, Emigdio [0000-0002-9783-0806], Chatterjee, Arindom, Banik, Ananya, Sachat, Alexandros el, Caicedo, José Manuel, Padilla-Pantoja, Jessica, Sotomayor Torres, C. M., Biswas, Kanishka, Santiso, José, and Chávez-Angel, Emigdio

Abstract

Layered Bi-misfit cobaltates, such as Bi2Sr2Co2Oy, are the natural superlattice of an electrically insulating rocksalt (RS) type Bi2Sr2O4 layer and electrically conducting CoO2 layer, stacked along the crystallographic c-axis. RS and CoO2 layers are related through charge compensation reactions (or charge transfer). Therefore, thermoelectric transport properties are affected when doping or substitution is carried out in the RS layer. In this work, we have shown improved thermoelectric properties of spark plasma sintered Bi2Sr2-xCaxCo2Oy alloys (x = 0, 0.3 and 0.5). The substitution of Ca atoms affects the thermal properties by introducing point-defect phonon scattering, while the electronic conductivity and thermopower remain unaltered.

Published
2023

23. Contactless characterization of the elastic properties of glass microspheres

Author

Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Economía y Competitividad (España), Maire, Jeremie [0000-0002-9921-4804], Necio, Tomasz [0000-0002-0232-1698], Chávez-Ángel, Emigdio [0000-0002-9783-0806], Jaramillo-Fernandez, Juliana [0000-0002-4787-3904], Sotomayor Torres, C. M. [0000-0001-9986-2716], Navarro-Urrios, Daniel [0000-0001-9055-1583], Maire, Jeremie, Necio, Tomasz, Chávez-Angel, Emigdio, Colombano, Martin F., Jaramillo-Fernandez, Juliana, Sotomayor Torres, C. M., Capuj, Néstor E., Navarro-Urrios, D., Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Economía y Competitividad (España), Maire, Jeremie [0000-0002-9921-4804], Necio, Tomasz [0000-0002-0232-1698], Chávez-Ángel, Emigdio [0000-0002-9783-0806], Jaramillo-Fernandez, Juliana [0000-0002-4787-3904], Sotomayor Torres, C. M. [0000-0001-9986-2716], Navarro-Urrios, Daniel [0000-0001-9055-1583], Maire, Jeremie, Necio, Tomasz, Chávez-Angel, Emigdio, Colombano, Martin F., Jaramillo-Fernandez, Juliana, Sotomayor Torres, C. M., Capuj, Néstor E., and Navarro-Urrios, D.

Abstract

Glass microspheres are of great interest for numerous industrial, biomedical, or standalone applications, but it remains challenging to evaluate their elastic and optical properties in a non-destructive way. In this work, we address this issue by using two complementary contactless techniques to obtain elastic and optical constants of glass microspheres with diameters ranging from 10 to 60 µm. The first technique we employ is Brillouin Light Scattering, which yields scattering with longitudinal acoustic phonons, the frequency of which is found to be 5% lower than that measured in the bulk material. The second technique involves exciting the optical whispering gallery modes of the microspheres, which allows us to transduce some of their vibrational modes. The combined data allow for extracting the refractive index and the elastic constants of the material. Our findings indicate that the values of those properties are reduced with respect to their bulk material counterpart due to an effective decrease of the density, resulting from the fabrication process. We propose the use of this combined method to extract elastic and optical parameters of glass materials in microsphere geometries and compare them with the values of the pristine material from which they are formed.

Published
2023

24. Application of Synchrotron Radiation-Based Fourier-Transform Infrared Microspectroscopy for Thermal Imaging of Polymer Thin Films

Author

European Commission, Generalitat de Catalunya, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Research Council of Norway, Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Chávez-Angel, Emigdio [0000-0002-9783-0806], Ng, Ryan C. [0000-0002-0527-9130], Sandell, Susanne [0000-0003-1906-6790], He, Jianying [0000-0001-8485-7893], Castro-Álvarez, Alejandro [0000-0001-8360-8027], Sotomayor Torres, C. M. [0000-0001-9986-2716], Kreuzer, Martin [0000-0002-7305-5016], Chávez-Angel, Emigdio, Ng, Ryan C., Sandell, Susanne, He, Jianying, Castro-Álvarez, Alejandro, Sotomayor Torres, C. M., Kreuzer, Martin, European Commission, Generalitat de Catalunya, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Research Council of Norway, Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Chávez-Angel, Emigdio [0000-0002-9783-0806], Ng, Ryan C. [0000-0002-0527-9130], Sandell, Susanne [0000-0003-1906-6790], He, Jianying [0000-0001-8485-7893], Castro-Álvarez, Alejandro [0000-0001-8360-8027], Sotomayor Torres, C. M. [0000-0001-9986-2716], Kreuzer, Martin [0000-0002-7305-5016], Chávez-Angel, Emigdio, Ng, Ryan C., Sandell, Susanne, He, Jianying, Castro-Álvarez, Alejandro, Sotomayor Torres, C. M., and Kreuzer, Martin

Abstract

The thermal imaging of surfaces with microscale spatial resolution over micro-sized areas remains a challenging and time-consuming task. Surface thermal imaging is a very important characterization tool in mechanical engineering, microelectronics, chemical process engineering, optics, microfluidics, and biochemistry processing, among others. Within the realm of electronic circuits, this technique has significant potential for investigating hot spots, power densities, and monitoring heat distributions in complementary metal-oxide-semiconductor (CMOS) platforms. We present a new technique for remote non-invasive, contactless thermal field mapping using synchrotron radiation-based Fourier-transform infrared microspectroscopy. We demonstrate a spatial resolution better than 10 um over areas on the order of 12,000 um2 measured in a polymeric thin film on top of CaF2 substrates. Thermal images were obtained from infrared spectra of poly(methyl methacrylate) thin films heated with a wire. The temperature dependence of the collected infrared spectra was analyzed via linear regression and machine learning algorithms, namely random forest and k-nearest neighbor algorithms. This approach speeds up signal analysis and allows for the generation of hyperspectral temperature maps. The results here highlight the potential of infrared absorbance to serve as a remote method for the quantitative determination of heat distribution, thermal properties, and the existence of hot spots, with implications in CMOS technologies and other electronic devices.

Published
2023

26. Probing the electron-phonon coupling in ozone-doped graphene by Raman spectroscopy

Author

Alzina, F., Tao, H., Moser, J., Garcia, Y., Bachtold, A., and Sotomayor-Torres, C. M.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We have investigated the effects of ozone treatment on graphene by Raman scattering. Sequential ozone short-exposure cycles resulted in increasing the $p$ doping levels as inferred from the blue shift of the 2$D$ and $G$ peak frequencies, without introducing significant disorder. The two-phonon 2$D$ and 2$D'$ Raman peak intensities show a significant decrease, while, on the contrary, the one-phonon G Raman peak intensity remains constant for the whole exposure process. The former reflects the dynamics of the photoexcited electrons (holes) and, specifically, the increase of the electron-electron scattering rate with doping. From the ratio of 2$D$ to 2$D$ intensities, which remains constant with doping, we could extract the ratio of electron-phonon coupling parameters. This ratio is found independent on the number of layers up to ten layers. Moreover, the rate of decrease of 2$D$ and 2$D'$ intensities with doping was found to slowdown inversely proportional to the number of graphene layers, revealing the increase of the electron-electron collision probability.

Published
2010
Full Text
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27. Quantum Thermometry with Single Molecules in Nanoprobes

Author

Universidad de Sevilla. Departamento de Física de la Materia Condensada, Gobierno de España, Generalitat de Catalunya, Esteso Carrizo, Victoria, Duquennoy, R., Ng, R. C., Colautti, M., Lombardi, P., Arregui, G., Chávez Ángel, E., Sotomayor Torres, C. M., García, P. D, Hilke, M., Toninelli, C., Universidad de Sevilla. Departamento de Física de la Materia Condensada, Gobierno de España, Generalitat de Catalunya, Esteso Carrizo, Victoria, Duquennoy, R., Ng, R. C., Colautti, M., Lombardi, P., Arregui, G., Chávez Ángel, E., Sotomayor Torres, C. M., García, P. D, Hilke, M., and Toninelli, C.

Abstract

An understanding of heat transport is relevant to developing efficient strategies for thermal management in areas of study such as microelectronics, as well as for fundamental science purposes. However, the measurement of temperatures in nanostructured environments and in cryogenic conditions remains a challenging task, requiring both high sensitivity and noninvasive approaches. Here, we present a portable nanothermometer based on a molecular two-level quantum system that operates in the (3-20)-K temperature range, with temperatures and spatial resolutions on the order of millikelvins and micrometers, respectively. We validate the performance of this molecular thermometer by estimating the thermal conductivity of a nanopatterned silicon membrane, where we find a quadratic temperature dependence. In addition, we demonstrate two-dimensional temperature mapping via the simultaneous spectroscopy of multiple probes deposited onto such a suspended membrane. Overall, these results demonstrate the unique potential of the proposed molecular thermometer to explore thermal properties with submicron accuracy and unveil related phenomena manifested at cryogenic temperatures.

Published
2023

28. Quantum Thermometry with Single Molecules in Nanoprobes

Author

Esteso, V., Duquennoy, R., Ng, R. C., Colautti, M., Lombardi, P., Arregui, G., Chavez-Angel, E., Sotomayor-Torres, C. M., Garcia, P. D., Hilke, M., Toninelli, C., Esteso, V., Duquennoy, R., Ng, R. C., Colautti, M., Lombardi, P., Arregui, G., Chavez-Angel, E., Sotomayor-Torres, C. M., Garcia, P. D., Hilke, M., and Toninelli, C.

Abstract

An understanding of heat transport is relevant to developing efficient strategies for thermal management in areas of study such as microelectronics, as well as for fundamental science purposes. However, the measurement of temperatures in nanostructured environments and in cryogenic conditions remains a challenging task, requiring both high sensitivity and noninvasive approaches. Here, we present a portable nanothermometer based on a molecular two-level quantum system that operates in the (3-20)-K temperature range, with temperatures and spatial resolutions on the order of millikelvins and micrometers, respectively. We validate the performance of this molecular thermometer by estimating the thermal conductivity of a nanopatterned silicon membrane, where we find a quadratic temperature dependence. In addition, we demonstrate two-dimensional temperature mapping via the simultaneous spectroscopy of multiple probes deposited onto such a suspended membrane. Overall, these results demonstrate the unique potential of the proposed molecular thermometer to explore thermal properties with submicron accuracy and unveil related phenomena manifested at cryogenic temperatures.

Published
2023

30. Supplementary information for Cavity optomechanics with Anderson-localized optical modes

Author

Arregui, Guillermo, Ng, Ryan C., Albrechtsen, Marcus, Stobbe, Søren, Sotomayor Torres, C. M., García, Pedro David, Arregui, Guillermo, Ng, Ryan C., Albrechtsen, Marcus, Stobbe, Søren, Sotomayor Torres, C. M., and García, Pedro David

Abstract

Supplementary material with stadistical analysis of the localization length, the quality-factors, the mode volumes and the optomechanical coupling rates.

Published
2023

31. Supplementary information of Enhanced behaviour of a passive thermoelectric generator with phase change heat exchangers and radiative cooling

Author

Astrain, David, Jaramillo-Fernandez, Juliana, Araiz, Miguel, Francone, Achille, Catalán, Leyre, Jacobo-Martín, Alejandra, Alegría, Patricia, Sotomayor Torres, C. M., Astrain, David, Jaramillo-Fernandez, Juliana, Araiz, Miguel, Francone, Achille, Catalán, Leyre, Jacobo-Martín, Alejandra, Alegría, Patricia, and Sotomayor Torres, C. M.

Published
2023

32. Emerging topics in nanophononics and elastic, acoustic, and mechanical metamaterials: An overview

Author

European Commission, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Krushynska, Anastasiia O. [0000-0003-3259-2592], Torrent, Daniel [0000-0001-7092-7360], Bilal, Osama R. [0000-0003-3803-5084], Bosia, Federico [0000-0002-2886-4519], Starkey, Timothy A. [0000-0001-6027-1046], Krushynska, Anastasiia O., Torrent, Daniel, Aragón, Alejandro M., Ardito, Raffaele, Bilal, Osama R., Bonello, Bernard, Bosia, Federico, Chen, Yi, Christensen, Johan, Colombi, Andrea, Cummer, Steven A., Djafari-Rouhani, Bahram, Fraternali, Fernando, Galich, Pavel I., García, Pedro David, Groby, Jean Philippe, Guenneau, Sebastien, Haberman, Michael R., Hussein, Mahmoud I., Janbaz, Shahram, Jiménez, Noé, Khelif, Abdelkrim, Laude, Vincent, Mirzaali, Mohammad J., Packo, Pawel, Palermo, Antonio, Pennec, Yan, Picó, Rubén, Rosendo López, María, Rudykh, Stephan, Serra-García, Marc, Sotomayor Torres, C. M., Starkey, Timothy A., Tournat, Vincent, Wright, Oliver B., European Commission, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Krushynska, Anastasiia O. [0000-0003-3259-2592], Torrent, Daniel [0000-0001-7092-7360], Bilal, Osama R. [0000-0003-3803-5084], Bosia, Federico [0000-0002-2886-4519], Starkey, Timothy A. [0000-0001-6027-1046], Krushynska, Anastasiia O., Torrent, Daniel, Aragón, Alejandro M., Ardito, Raffaele, Bilal, Osama R., Bonello, Bernard, Bosia, Federico, Chen, Yi, Christensen, Johan, Colombi, Andrea, Cummer, Steven A., Djafari-Rouhani, Bahram, Fraternali, Fernando, Galich, Pavel I., García, Pedro David, Groby, Jean Philippe, Guenneau, Sebastien, Haberman, Michael R., Hussein, Mahmoud I., Janbaz, Shahram, Jiménez, Noé, Khelif, Abdelkrim, Laude, Vincent, Mirzaali, Mohammad J., Packo, Pawel, Palermo, Antonio, Pennec, Yan, Picó, Rubén, Rosendo López, María, Rudykh, Stephan, Serra-García, Marc, Sotomayor Torres, C. M., Starkey, Timothy A., Tournat, Vincent, and Wright, Oliver B.

Abstract

This broad review summarizes recent advances and "hot"research topics in nanophononics and elastic, acoustic, and mechanical metamaterials based on results presented by the authors at the EUROMECH 610 Colloquium held on April 25-27, 2022 in Benicássim, Spain. The key goal of the colloquium was to highlight important developments in these areas, particularly new results that emerged during the last two years. This work thus presents a "snapshot"of the state-of-the-art of different nanophononics- and metamaterial-related topics rather than a historical view on these subjects, in contrast to a conventional review article. The introduction of basic definitions for each topic is followed by an outline of design strategies for the media under consideration, recently developed analysis and implementation techniques, and discussions of current challenges and promising applications. This review, while not comprehensive, will be helpful especially for early-career researchers, among others, as it offers a broad view of the current state-of-the-art and highlights some unique and flourishing research in the mentioned fields, providing insight into multiple exciting research directions.

Published
2023

33. Supplementary Materials Application of Synchrotron Radiation-Based Fourier-Transform Infrared Microspectroscopy for Thermal Imaging of Polymer Thin Films

Author

Chávez-Angel, Emigdio [emigdio.chavez@icn2.cat], Kreuzer, Martin [mkreuzer@cells.es], Chávez-Angel, Emigdio, Ng, Ryan C., Sandell, Susanne, He, Jianying, Castro-Álvarez, Alejandro, Sotomayor Torres, C. M., Kreuzer, Martin, Chávez-Angel, Emigdio [emigdio.chavez@icn2.cat], Kreuzer, Martin [mkreuzer@cells.es], Chávez-Angel, Emigdio, Ng, Ryan C., Sandell, Susanne, He, Jianying, Castro-Álvarez, Alejandro, Sotomayor Torres, C. M., and Kreuzer, Martin

Published
2023

34. Supplementary Material: Contactless characterization of the elastic properties of glass microspheres

Author

Navarro-Urrios, Daniel [dnavarro@ub.edu], Maire, Jeremie, Necio, Tomasz, Chávez-Angel, Emigdio, Colombano, Martin F., Jaramillo-Fernandez, Juliana, Sotomayor Torres, C. M., Capuj, Néstor E., Navarro-Urrios, D., Navarro-Urrios, Daniel [dnavarro@ub.edu], Maire, Jeremie, Necio, Tomasz, Chávez-Angel, Emigdio, Colombano, Martin F., Jaramillo-Fernandez, Juliana, Sotomayor Torres, C. M., Capuj, Néstor E., and Navarro-Urrios, D.

Published
2023

35. Enhanced behaviour of a passive thermoelectric generator with phase change heat exchangers and radiative cooling

Author

Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Universidad Pública de Navarra, Astrain, David [0000-0002-6987-0640], Araiz, Miguel [0000-0002-7674-0078], Catalán, Leyre [0000-0003-0140-6689], Jacobo-Martín, Alejandra [0000-0003-2404-2881], Astrain, David, Jaramillo-Fernandez, Juliana, Araiz, Miguel, Francone, Achille, Catalán, Leyre, Jacobo-Martín, Alejandra, Alegría, Patricia, Sotomayor Torres, C. M., Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Universidad Pública de Navarra, Astrain, David [0000-0002-6987-0640], Araiz, Miguel [0000-0002-7674-0078], Catalán, Leyre [0000-0003-0140-6689], Jacobo-Martín, Alejandra [0000-0003-2404-2881], Astrain, David, Jaramillo-Fernandez, Juliana, Araiz, Miguel, Francone, Achille, Catalán, Leyre, Jacobo-Martín, Alejandra, Alegría, Patricia, and Sotomayor Torres, C. M.

Abstract

Heat exchangers are essential to optimize the efficiency of Thermoelectric Generators (TEGs), and heat pipes without fans have proven to be an advantageous design as it maintains the characteristic robustness of thermoelectricity, low maintenance and lack of moving parts. However, the efficiency of these heat exchangers decreases under natural convection conditions, reducing their heat transfer capacity and thus thermoelectric power production. This work reports on a novel heat exchanger that combines for the first time, phase change and radiative cooling in a thermoelectric generator to improve its efficiency and increase the production of electrical energy, specially under natural convection. For this, two thermoelectric generators with heat-pipes on their cold sides have been tested: one with the radiative coating and the other without it. Their thermal resistances have been determined and the electric power output was compared under different working conditions, namely, natural convection and forced convection indoors and outdoors. The experimental tests show a clear reduction of the heat exchanger thermal resistance thanks to the radiative coating and consequently, an increase of electric production 8.3 % with outdoor wind velocities of 1 m/s, and up to 54.8 % under free convection conditions. The application of the radiative surface treatment is shown to result in a more stable electrical energy production, suppressing the drastic decrease in the generated electric power that occurs in thermoelectric generators when they work under free convection.

Published
2023

36. Quantum thermometry with single molecules in nanoprobes

Author

European Commission, European Research Council, Ministerio de Universidades (España), Universidad de Sevilla, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, Ministerio de Ciencia e Innovación (España), Esteso, Victoria, Duquennoy, R., Ng, Ryan C., Colautti, M., Lombardi, P., Arregui, Guillermo, Chávez-Angel, Emigdio, Sotomayor Torres, C. M., García Fernández, Pedro David, Hilke, M., Toninelli, C., European Commission, European Research Council, Ministerio de Universidades (España), Universidad de Sevilla, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, Ministerio de Ciencia e Innovación (España), Esteso, Victoria, Duquennoy, R., Ng, Ryan C., Colautti, M., Lombardi, P., Arregui, Guillermo, Chávez-Angel, Emigdio, Sotomayor Torres, C. M., García Fernández, Pedro David, Hilke, M., and Toninelli, C.

Abstract

An understanding of heat transport is relevant to developing efficient strategies for thermal management in areas of study such as microelectronics, as well as for fundamental science purposes. However, the measurement of temperatures in nanostructured environments and in cryogenic conditions remains a challenging task, requiring both high sensitivity and noninvasive approaches. Here, we present a portable nanothermometer based on a molecular two-level quantum system that operates in the (3–20)-K temperature range, with temperatures and spatial resolutions on the order of millikelvins and micrometers, respectively. We validate the performance of this molecular thermometer by estimating the thermal conductivity of a nanopatterned silicon membrane, where we find a quadratic temperature dependence. In addition, we demonstrate two-dimensional temperature mapping via the simultaneous spectroscopy of multiple probes deposited onto such a suspended membrane. Overall, these results demonstrate the unique potential of the proposed molecular thermometer to explore thermal properties with submicron accuracy and unveil related phenomena manifested at cryogenic temperatures.

Published
2023

37. Supporting Information for: Enhanced thermal conductivity of free-standing double-walled carbon nanotube networks

Author

Mehew, Jake D., Timmermans, Marina Y., Saleta Reig, David, Sergeant, Stefanie, Sledzinska, Marianna, Chávez-Angel, Emigdio, Gallagher, Emily, Sotomayor Torres, C. M., Huyghebaert, C., Tielrooij, Klaas-Jan, Mehew, Jake D., Timmermans, Marina Y., Saleta Reig, David, Sergeant, Stefanie, Sledzinska, Marianna, Chávez-Angel, Emigdio, Gallagher, Emily, Sotomayor Torres, C. M., Huyghebaert, C., and Tielrooij, Klaas-Jan

Published
2023

38. Enhanced thermal conductivity of free-standing double-walled carbon nanotube networks

Author

Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), European Commission, European Research Council, Mehew, Jake D., Timmermans, Marina Y., Saleta Reig, David, Sergeant, Stefanie, Sledzinska, Marianna, Chávez-Angel, Emigdio, Gallagher, Emily, Sotomayor Torres, C. M., Huyghebaert, C., Tielrooij, Klaas-Jan, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), European Commission, European Research Council, Mehew, Jake D., Timmermans, Marina Y., Saleta Reig, David, Sergeant, Stefanie, Sledzinska, Marianna, Chávez-Angel, Emigdio, Gallagher, Emily, Sotomayor Torres, C. M., Huyghebaert, C., and Tielrooij, Klaas-Jan

Abstract

Nanomaterials are driving advances in technology due to their oftentimes superior properties over bulk materials. In particular, their thermal properties become increasingly important as efficient heat dissipation is required to realize high-performance electronic devices, reduce energy consumption, and prevent thermal damage. One application where nanomaterials can play a crucial role is extreme ultraviolet (EUV) lithography, where pellicles that protect the photomask from particle contamination have to be transparent to EUV light, mechanically strong, and thermally conductive in order to withstand the heat associated with high-power EUV radiation. Free-standing carbon nanotube (CNT) films have emerged as candidates due to their high EUV transparency and ability to withstand heat. However, the thermal transport properties of these films are not well understood beyond bulk emissivity measurements. Here, we measure the thermal conductivity of free-standing CNT films using all-optical Raman thermometry at temperatures between 300 and 700 K. We find thermal conductivities up to 50 W m–1 K–1 for films composed of double-walled CNTs, which rises to 257 W m–1 K–1 when considering the CNT network alone. These values are remarkably high for randomly oriented CNT networks, roughly seven times that of single-walled CNT films. The enhanced thermal conduction is due to the additional wall, which likely gives rise to additional heat-carrying phonon modes and provides a certain resilience to defects. Our results demonstrate that free-standing double-walled CNT films efficiently dissipate heat, enhancing our understanding of these promising films and how they are suited to applications in EUV lithography.

Published
2023

39. Supporting Information: Engineering heat transport across epitaxial lattice-mismatched van der Waals heterointerfaces

Author

Chávez-Angel, Emigdio, Tsipas, Polychronis, Xiao, Peng, Ahmadi, Mohammad Taghi, Daaoub, Abdalghani H. S., Sadeghi, Hatef, Sotomayor Torres, C. M., Dimoulas, Athanasios, Sachat, Alexandros el, Chávez-Angel, Emigdio, Tsipas, Polychronis, Xiao, Peng, Ahmadi, Mohammad Taghi, Daaoub, Abdalghani H. S., Sadeghi, Hatef, Sotomayor Torres, C. M., Dimoulas, Athanasios, and Sachat, Alexandros el

Published
2023

40. Engineering heat transport across epitaxial lattice-mismatched van der Waals heterointerfaces

Author

European Commission, European Research Council, Generalitat de Catalunya, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Chávez-Angel, Emigdio, Tsipas, Polychronis, Xiao, Peng, Ahmadi, Mohammad Taghi, Daaoub, Abdalghani H. S., Sadeghi, Hatef, Sotomayor Torres, C. M., Dimoulas, Athanasios, Sachat, Alexandros el, European Commission, European Research Council, Generalitat de Catalunya, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Chávez-Angel, Emigdio, Tsipas, Polychronis, Xiao, Peng, Ahmadi, Mohammad Taghi, Daaoub, Abdalghani H. S., Sadeghi, Hatef, Sotomayor Torres, C. M., Dimoulas, Athanasios, and Sachat, Alexandros el

Abstract

Artificially engineered 2D materials offer unique physical properties for thermal management, surpassing naturally occurring materials. Here, using van der Waals epitaxy, we demonstrate the ability to engineer extremely insulating thermal metamaterials based on atomically thin lattice-mismatched Bi2Se3/MoSe2 superlattices and graphene/PdSe2 heterostructures with exceptional thermal resistances (70–202 m2 K/GW) and ultralow cross-plane thermal conductivities (0.012–0.07 W/mK) at room temperature, comparable to those of amorphous materials. Experimental data obtained using frequency-domain thermoreflectance and low-frequency Raman spectroscopy, supported by tight-binding phonon calculations, reveal the impact of lattice mismatch, phonon-interface scattering, size effects, temperature, and interface thermal resistance on cross-plane heat dissipation, uncovering different thermal transport regimes and the dominant role of long-wavelength phonons. Our findings provide essential insights into emerging synthesis and thermal characterization methods and valuable guidance for the development of large-area heteroepitaxial van der Waals films of dissimilar materials with tailored thermal transport characteristics.

Published
2023

44. Dataset related to the publication 'Thermal properties of nanocrystalline silicon nanobeams'

Author

European Commission, Maire, Jeremie [0000-0002-9921-4804], Chávez-Angel, Emigdio [0000-0002-9783-0806], Arregui, Guillermo [0000-0002-6458-5277], Colombano, Martin F. [0000-0002-2003-8597], Griol, Amadeu [0000-0002-5428-5713], Martínez, Alejandro [0000-0001-5448-0140], Navarro-Urrios, D. [0000-0001-9055-1583], Ahopelto, Jouni [0000-0003-3372-6097], Sotomayor Torres, C. M. [0000-0001-9986-2716], Maire, Jeremie, Chávez-Angel, Emigdio, Arregui, Guillermo, Colombano, Martin F., Capuj, Néstor E., Griol, Amadeu, Martínez, Alejandro, Navarro-Urrios, D., Ahopelto, Jouni, Sotomayor Torres, C. M., European Commission, Maire, Jeremie [0000-0002-9921-4804], Chávez-Angel, Emigdio [0000-0002-9783-0806], Arregui, Guillermo [0000-0002-6458-5277], Colombano, Martin F. [0000-0002-2003-8597], Griol, Amadeu [0000-0002-5428-5713], Martínez, Alejandro [0000-0001-5448-0140], Navarro-Urrios, D. [0000-0001-9055-1583], Ahopelto, Jouni [0000-0003-3372-6097], Sotomayor Torres, C. M. [0000-0001-9986-2716], Maire, Jeremie, Chávez-Angel, Emigdio, Arregui, Guillermo, Colombano, Martin F., Capuj, Néstor E., Griol, Amadeu, Martínez, Alejandro, Navarro-Urrios, D., Ahopelto, Jouni, and Sotomayor Torres, C. M.

Abstract

Dataset contains the raw data from which the graphs in paper "Thermal properties of nanocrystalline silicon nanobeams".

Published
2021

46. Nanoscale Mapping of Thermal and Mechanical Properties of Bare and Metal-Covered Self-Assembled Block Copolymer Thin Films

Author

European Commission, Engineering and Physical Sciences Research Council (UK), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Generalitat de Catalunya, Sachat, Alexandros el [0000-0003-3798-9724], Evangeli, Charalambos [0000-0003-3867-8530], Kreuzer, Martin [0000-0002-7305-5016], Rodríguez-Laguna, María del Rocío [0000-0001-5582-1728], Chávez-Angel, Emigdio [0000-0002-9783-0806], Sledzinska, Marianna [0000-0001-8592-1121], Sotomayor Torres, C. M. [0000-0001-9986-2716], Kolosov, Oleg V. [0000-0003-3278-9643], Sachat, Alexandros el, Spièce, Jean, Evangeli, Charalambos, Robson, Alexander James, Kreuzer, Martin, Rodríguez-Laguna, María del Rocío, Chávez-Angel, Emigdio, Sledzinska, Marianna, Sotomayor Torres, C. M., Kolosov, Oleg V., Alzina, Francesc, European Commission, Engineering and Physical Sciences Research Council (UK), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Generalitat de Catalunya, Sachat, Alexandros el [0000-0003-3798-9724], Evangeli, Charalambos [0000-0003-3867-8530], Kreuzer, Martin [0000-0002-7305-5016], Rodríguez-Laguna, María del Rocío [0000-0001-5582-1728], Chávez-Angel, Emigdio [0000-0002-9783-0806], Sledzinska, Marianna [0000-0001-8592-1121], Sotomayor Torres, C. M. [0000-0001-9986-2716], Kolosov, Oleg V. [0000-0003-3278-9643], Sachat, Alexandros el, Spièce, Jean, Evangeli, Charalambos, Robson, Alexander James, Kreuzer, Martin, Rodríguez-Laguna, María del Rocío, Chávez-Angel, Emigdio, Sledzinska, Marianna, Sotomayor Torres, C. M., Kolosov, Oleg V., and Alzina, Francesc

Abstract

We report on the structural, mechanical, and thermal analysis of 40 nm thick polystyrene-block-poly(ethylene oxide) (PS-b-PEO) block copolymer (BCP) films coated with evaporated chromium layers of different thicknesses (1, 2, and 5 nm). Solvent annealing processes allow the structural control of the BCP films morphology by rearranging the position of the PEO cylinders parallel to the substrate plane. High-vacuum scanning thermal microscopy and ultrasonic force microscopy measurements performed in ambient pressure revealed that coated ultrathin metal layers strongly influence the heat dissipation in the BCP films and the local surface stiffness of the individual BCP domains, respectively. The measured tip-sample effective thermal resistance decreases from 6.1 × 107 to 2.5 × 107 K W-1 with increasing Cr film thickness. In addition, scanning probe microscopy measurements allow the thermal and mechanical mapping of the two segregated polymer domains (PEO-PS) of sub-50 nm characteristic sizes, with sub-10 nm thermal spatial resolution. The results revealed the effect of the surface morphology of the BCP and the incorporation of the metal film on the nanoscale thermal properties and volume self-assembly on the mechanical properties. The findings from this study provide insight into the formation of high aspect ratio BCP-metal structures with the more established applications in lithography. In addition, knowledge of the thermal and mechanical properties at the nanoscale is required in emergent applications, where BCPs, or polymers in general, are part of the structure or device. The performance of such devices is commonly related to the requirement of increased heat dissipation while maintaining mechanical flexibility.

Published
2020

49. Supporting Information for Adv. Mater., DOI: 10.1002/adma.202108352 Unraveling Heat Transport and Dissipation in Suspended MoSe2 from Bulk to Monolayer

Author

Generalitat de Catalunya, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Tielrooij, Klaas-Jan [klaas.tielrooij@icn2.cat], Saleta Reig, David, Varghese, Sebin, Farris, Roberta, Block, Alexander, Mehew, Jake D., Hellman, Olle, Woźniak, Pawel, Sledzinska, Marianna, Sachat, Alexandros el, Chávez-Angel, Emigdio, Valenzuela, Sergio O., Hulst, Niek F. van, Ordejón, Pablo, Zanolli, Zeila, Sotomayor Torres, C. M., Verstraete, Matthieu J., Tielrooij, Klaas-Jan, Generalitat de Catalunya, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Tielrooij, Klaas-Jan [klaas.tielrooij@icn2.cat], Saleta Reig, David, Varghese, Sebin, Farris, Roberta, Block, Alexander, Mehew, Jake D., Hellman, Olle, Woźniak, Pawel, Sledzinska, Marianna, Sachat, Alexandros el, Chávez-Angel, Emigdio, Valenzuela, Sergio O., Hulst, Niek F. van, Ordejón, Pablo, Zanolli, Zeila, Sotomayor Torres, C. M., Verstraete, Matthieu J., and Tielrooij, Klaas-Jan

Published
2022

50. Supplementary material Spectroscopic and thermal characterization of extra virgin olive oil adulterated with edible oils

Author

Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, Chávez-Angel, Emigdio [emigdio.chavez@icn2.cat], Castro-Alvarez, Alejandro [Alejandro.castro.a@ufrontera.cl], Chávez-Angel, Emigdio, Puertas, Belén, Kreuzer, Martin, Soliva Fortuny, Robert, Ng, Ryan C., Castro-Álvarez, Alejandro, Sotomayor Torres, C. M., Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, Chávez-Angel, Emigdio [emigdio.chavez@icn2.cat], Castro-Alvarez, Alejandro [Alejandro.castro.a@ufrontera.cl], Chávez-Angel, Emigdio, Puertas, Belén, Kreuzer, Martin, Soliva Fortuny, Robert, Ng, Ryan C., Castro-Álvarez, Alejandro, and Sotomayor Torres, C. M.

Published
2022

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