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51. Fabrication of Nano-Scale Gaps in Integrated Circuits

Author

Krahne, Roman, Dadosh, Tali, Yacoby, Amir, Shtrikman, Hadas, Sperling, Joseph, and Bar-Joseph, Israel

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Nano-size objects like metal clusters present an ideal system for the study of quantum phenomena and for constructing practical quantum devices. Integrating these small objects in a macroscopic circuit is, however, a difficult task. So far the nanoparticles have been contacted and addressed by highly sophisticated techniques which are not suitable for large scale integration in macroscopic circuits. We present an optical lithography method that allows for the fabrication of a network of electrodes which are separated by gaps of controlled nanometer size. The main idea is to control the gap size with subnanometer precision using a structure grown by molecular beam epitaxy., Comment: 4 pages, 3 figures

Published
2002
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52. From single dots to interacting arrays

Author

Gudmundsson, Vidar, Manolescu, Andrei, Krahne, Roman, and Heitmann, Detlef

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We explore the structural changes in charge the density and the electron configuration of quantum dots caused by the presence of other dots in an array, and the interaction of neighboring dots. We discuss what recent measurements and calculation of the far-infrared absorption reveal about almost isolated quantum dots and investigate some aspects of the complex transition from isolated dots to dots with strongly overlapping electron density. We also address the the effects on the magnetization of such dot array., Comment: 29 papes, 17 included figures. This article is slated to appear as a chapter in "Nano-Physics and Bio-Electronics", edited by T. Chakraborty, F. Peeters, and U. Sivan (to be published by Elsevier Co.)

Published
2001

53. Far-Infrared Excitations below the Kohn Mode: Internal Motion in a Quantum Dot

Author

Krahne, Roman, Gudmundsson, Vidar, Heyn, Christian, and Heitmann, Detlef

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We have investigated the far-infrared response of quantum dots in modulation doped GaAs heterostructures. We observe novel modes at frequencies below the center-of-mass Kohn mode. Comparison with Hartree-RPA calculations show that these modes arise from the flattened potential in our field-effect confined quantum dots. They reflect pronounced relative motion of the charge density with respect to the center-of-mass., Comment: 8 pages, LaTeX with integrated 6 PostScript figures

Published
2001
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56. Plasmonic Photochemistry as a Tool to Prepare Metallic Nanopores with Controlled Diameter for Optimized Detection of Single Entities

Author

Lanzavecchia, German, primary, Kuttruff, Joel, additional, Doricchi, Andrea, additional, Douaki, Ali, additional, Kumaranchira Ramankutty, Krishnadas, additional, García, Isabel, additional, Lin, Lyuye, additional, Viejo Rodríguez, Alba, additional, Wågberg, Thomas, additional, Krahne, Roman, additional, Maccaferri, Nicolò, additional, and Garoli, Denis, additional

Published
2023
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57. Nanostructures for Photonics

Author

Toma, Andrea, Zaccaria, Remo Proietti, Krahne, Roman, Alabastri, Alessandro, Coluccio, Maria Laura, Das, Gobind, Liberale, Carlo, De Angelis, Francesco, Francardi, Marco, Mecarini, Federico, Gentile, Francesco, Accardo, Angelo, Manna, Liberato, Di Fabrizio, Enzo, and Bhushan, Bharat, editor

Published
2016
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59. Micro‐ and Nano‐Structured Bacteria Growth Media for Planar Bio‐Photonics.

Author

Caligiuri, Vincenzo, Leone, Francesca, Favale, Olga, De Santo, Maria, Bruno, Mauro Daniel Luigi, Mileti, Olga, Pane, Alfredo, Patra, Aniket, Petti, Lucia, Guzman‐Puyol, Susana, Heredia‐Guerrero, José Alejandro, Krahne, Roman, Baldino, Noemi, Bartolino, Roberto, Galluccio, Michele, Annesi, Ferdinanda, and De Luca, Antonio

Subjects
PHOTONIC crystals, BIOMATERIALS, BACTERIAL growth, QUASICRYSTALS, BACTERIA, QUANTUM optics
Abstract

Bio‐inspired and biodegradable quantum optics scenarios constitute a pathway toward environmentally friendly front‐end technologies. Such an inspiring perspective necessitates the replacement of classic gain materials with a biological counterpart like photoluminescent bacteria. It is easy to imagine that, in this case, a planar and cell‐viable substitute of classic bulk solid‐states resonators can be highly beneficial. In this paper a micro‐ and nano‐photonic structuration of both a standard and a functionalized version of a typical bacterial growth medium (Luria‐Bertani Agar – LBA) is successfully realized. Three structures belonging to the categories of photonic crystals are replicated, such as quasi‐crystals and meta‐surfaces, demonstrating how the proposed media can be used as templates for high‐end photonic applications. The optical quality of the replicated structures is confirmed by far‐field diffraction measurements. The structured growth media allow for a broad control of the surface wettability by accessing a so‐called Wenzel state, in which the original hydrophilicity of a material is increased due to the photonic structuration. Finally, the suitability of the nano‐structured LBA as a plasmonic platform is evidenced. The proposed micro‐and nano‐structured photonic growth media constitute the first, fundamental step toward quantum optical frameworks from biological media. [ABSTRACT FROM AUTHOR]

Published
2024
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60. Optical Properties of Semiconductor Nanorods

Author

Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, Deka, Sasanka, Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, and Deka, Sasanka

Published
2013
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61. Outlook

Author

Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, Deka, Sasanka, Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, and Deka, Sasanka

Published
2013
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63. Catalytic Properties of Nanorods

Author

Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, Deka, Sasanka, Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, and Deka, Sasanka

Published
2013
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64. Electrical Properties of Nanorods

Author

Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, Deka, Sasanka, Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, and Deka, Sasanka

Published
2013
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65. Optical Properties of Metal Nanorods

Author

Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, Deka, Sasanka, Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, and Deka, Sasanka

Published
2013
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66. Quantum Effects in Confined Systems

Author

Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, Deka, Sasanka, Krahne, Roman, Manna, Liberato, Morello, Giovanni, Figuerola, Albert, George, Chandramohan, and Deka, Sasanka

Published
2013
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69. Plasmonic photochemistry as a tool to prepare metallic nanopores with controlled diameter for optimized detection of single entities

Author

Lanzavecchia, German, Kuttruff, Joel, Doricchi, Andrea, Douaki, Ali, Kumaranchira Ramankutty, Krishnadas, García, Isabel, Lin, Lyuye, Viejo Rodríguez, Alba, Wågberg, Thomas, Krahne, Roman, Maccaferri, Nicolò, Garoli, Denis, Lanzavecchia, German, Kuttruff, Joel, Doricchi, Andrea, Douaki, Ali, Kumaranchira Ramankutty, Krishnadas, García, Isabel, Lin, Lyuye, Viejo Rodríguez, Alba, Wågberg, Thomas, Krahne, Roman, Maccaferri, Nicolò, and Garoli, Denis

Abstract

Plasmonic solid-state nanopores with tunable hole diameters can be prepared via a photocatalytic effect resulting from the enhanced electromagnetic (EM) field inside a metallic ring on top of a dielectric nanotube. Under white light illumination, the plasmon-enhanced EM-field induces a site-selective metal nucleation and growth within the ring. This approach is used to prepare Au and bimetallic Au–Ag nano-rings and demonstrate the reduction of the initial inner diameter of the nanopore down to 4 nm. The tunability of the nanopore diameter can be used to enable optimized detection of single entities with different sizes. As a proof-of-concept, single object detection of double stranded DNA (dsDNA) and Au nanoparticles (AuNPs) with a diameter down to 15 nm is performed. Numerical simulations provide insights into the EM-field distribution and confinement, showing that a field intensity enhancement of up to 104 can be achieved inside the nanopores. This localized EM-field can be used to perform enhanced optical measurements and generate local heating, thereby modifying the properties of the nanopore. Such a flexible approach also represents a valuable tool to investigate plasmon-driven photochemical reactions, and it can represent an important step toward the realization of new plasmonic devices.

Published
2023
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70. Excitons and their fine structure in lead halide Perovskite nanocrystals from atomistic GW/BSE calculations

Author

European Commission, Air Force Office of Scientific Research (US), National Institutes of Health (US), Simons Foundation, Flatiron Institute, Empire State Development, New York, Columbia University, Biffi, Giulia, Cho, Yeongsu, Krahne, Roman, Berkelbach, Timothy C., European Commission, Air Force Office of Scientific Research (US), National Institutes of Health (US), Simons Foundation, Flatiron Institute, Empire State Development, New York, Columbia University, Biffi, Giulia, Cho, Yeongsu, Krahne, Roman, and Berkelbach, Timothy C.

Abstract

Atomistically detailed computational studies of nanocrystals, such as those derived from the promising lead-halide perovskites, are challenging due to the large number of atoms and lack of symmetries to exploit. Here, focusing on methylammonium lead iodide nanocrystals, we combine a real-space tight binding model with the GW approximation to the self-energy and obtain exciton wave functions and absorption spectra via solutions of the associated Bethe–Salpeter equation. We find that the size dependence of carrier confinement, dielectric contrast, electron–hole exchange, and exciton binding energies has a strong impact on the lowest excitation energy, which can be tuned by almost 1 eV over the diameter range of 2–6 nm. Our calculated excitation energies are about 0.2 eV higher than experimentally measured photoluminescence, and they display the same qualitative size dependence. Focusing on the fine structure of the band-edge excitons, we find that the lowest-lying exciton is spectroscopically dark and about 20–30 meV lower in energy than the higher-lying triplet of the bright states whose degeneracy is slightly broken by crystal field effects.

Published
2023

72. Metal Structures as Advanced Materials in Nanotechnology

Author

Accardo, Angelo, Proietti Zaccaria, Remo, Candeloro, Patrizio, Gentile, Francesco, Coluccio, Maria Laura, Das, Gobind, Krahne, Roman, Liberale, Carlo, Toma, Andrea, Panaro, Simone, Miele, Ermanno, Chirumamilla, Manohar, Rajamanickam, Vijayakumar, Di Fabrizio, Enzo, Bhushan, Bharat, editor, Luo, Dan, editor, Schricker, Scott R., editor, Sigmund, Wolfgang, editor, and Zauscher, Stefan, editor

Published
2014
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73. Chapter Photonic Crystals for Plasmonics: From Fundamentals to Superhydrophobic Devices

Author

Gentile, Francesco, Razzari, Luca, Proietti Zaccaria, Remo, Das, Gobind, Liberale, Carlo, Haddadpour, Ali, Giugni, Andrea, Gopalakrishnan, Anisha, De Angelis, Francesco, Krahne, Roman, Toma, Andrea, Mecarini, F., and Di Fabrizio, Enzo

Subjects
Technology, engineering, agriculture, bic Book Industry Communication::T Technology, engineering, agriculture::TG Mechanical engineering & materials::TGP Production engineering
Abstract

Production engineering

Published
2012
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74. Engineering 3D Multi-Branched Nanostructures for Ultra- Sensing Applications

Author

Chirumamilla, Anisha, primary, Chirumamilla, Manohar, additional, Roberts, Alexander S., additional, Cerea, Andrea, additional, Skovsen, Esben, additional, Angelis, Francesco De, additional, Zaccaria, Remo Proietti, additional, Kristensen, Peter Kjær, additional, Krahne, Roman, additional, Sutherland, Duncan S., additional, Bozhevolnyi, Sergey I., additional, Pedersen, Kjeld, additional, and Toma, Andrea, additional

Published
2018
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80. Nanostructures for Photonics

Author

Toma, Andrea, Zaccaria, Remo Proietti, Krahne, Roman, Alabastri, Alessandro, Coluccio, Maria Laura, Das, Gobind, Liberale, Carlo, De Angelis, Francesco, Francardi, Marco, Mecarini, Federico, Gentile, Francesco, Accardo, Angelo, Manna, Liberato, Di Fabrizio, Enzo, and Bhushan, Bharat, editor

Published
2012
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81. Emerging Approaches to DNA Data Storage: Challenges and Prospects

Author

Doricchi, Andrea, primary, Platnich, Casey M., additional, Gimpel, Andreas, additional, Horn, Friederikee, additional, Earle, Max, additional, Lanzavecchia, German, additional, Cortajarena, Aitziber L., additional, Liz-Marzán, Luis M., additional, Liu, Na, additional, Heckel, Reinhard, additional, Grass, Robert N., additional, Krahne, Roman, additional, Keyser, Ulrich F., additional, and Garoli, Denis, additional

Published
2022
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82. Mixed Organic Cations Promote Ambient Light-Induced Formation of Metallic Lead in Lead Halide Perovskite Crystals.

Author

Ray, Aniruddha, Martín-García, Beatriz, Prato, Mirko, Moliterni, Anna, Bordignon, Simone, Spirito, Davide, Marras, Sergio, Goldoni, Luca, Boopathi, Karunakara Moorthy, Moro, Fabrizio, Casati, Nicola Pietro Maria, Giacobbe, Carlotta, Saidaminov, Makhsud I., Giannini, Cinzia, Chierotti, Michele R., Krahne, Roman, Manna, Liberato, and Abdelhady, Ahmed L.

Published
2023
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83. Radiative volume plasmon and phonon-polariton resonances in TiN-based plasmonic/polar-dielectric hyperbolic optical metamaterials.

Author

Maurya, Krishna Chand, Caligiuri, Vincenzo, Pillai, Ashalatha Indiradevi Kamalasanan, Garbrecht, Magnus, Krahne, Roman, and Saha, Bivas

Subjects
POLARITONS, SURFACE plasmon resonance, METAMATERIALS, RESONANCE, METALLIC films, SURFACE plasmons, THIN films, SUPERLATTICES
Abstract

Ferrell and Berreman modes are absorption resonances in thin metal films and polar-dielectric media that arise from radiative bulk plasmon-polariton and phonon-polariton excitations. Compared to surface polaritons, Ferrell and Berreman modes occur due to volume charge oscillations across the medium and provide a unique pathway for light–matter interactions. Though the resonances are studied individually, stringent polarization and material requirements have prevented their observation in one host medium. Here, we show simultaneous excitation of Ferrell and Berreman absorption resonances in refractory epitaxial TiN/Al0.72Sc0.28N plasmonic metal/polar-dielectric hyperbolic metamaterials in the visible and far-infrared spectral ranges. The nanoscale periodicity of the superlattices enables the coupling of bulk plasmons (and longitudinal optical phonons) across different TiN (and Al0.72Sc0.28N) layers and allows polarization matching with free-space light that results in Ferrell (and Berreman) mode excitations. Ferrell and Berreman absorption resonances can be used for strong light confinement in radiative cooling, thermophotovoltaics, and other dual-band applications. [ABSTRACT FROM AUTHOR]

Published
2023
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90. Correlating symmetries of low-frequency vibrations and self-trapped excitons in layered perovskites for light emission with different colors

Author

European Commission, Ministero degli Affari Esteri e della Cooperazione Internazionale, National Natural Science Foundation of China, China Postdoctoral Science Foundation, National Key Research and Development Program (China), Lin, Miao-Ling, Dhanabalan, Balaji, Biffi, Giulia, Leng, Yu-Chen, Kutkan, Seda, Arciniegas, Milena P., Tan, Ping-Heng, Krahne, Roman, European Commission, Ministero degli Affari Esteri e della Cooperazione Internazionale, National Natural Science Foundation of China, China Postdoctoral Science Foundation, National Key Research and Development Program (China), Lin, Miao-Ling, Dhanabalan, Balaji, Biffi, Giulia, Leng, Yu-Chen, Kutkan, Seda, Arciniegas, Milena P., Tan, Ping-Heng, and Krahne, Roman

Abstract

The soft hybrid organic–inorganic structure of two-dimensional layered perovskites (2DLPs) enables broadband emission at room temperature from a single material, which makes 2DLPs promising sources for solid-state white lighting, yet with low efficiency. The underlying photophysics involves self-trapping of excitons favored by distortions of the inorganic lattice and coupling to phonons, where the mechanism is still under debate. 2DLPs with different organic moieties and emission ranging from self-trapped exciton (STE)-dominated white light to blue band-edge photoluminescence are investigated. Detailed insights into the directional symmetries of phonon modes are gained using angle-resolved polarized Raman spectroscopy and are correlated to the temperature-dependence of the STE emission. It is demonstrated that weak STE bands at low-temperature are linked to in-plane phonons, and efficient room-temperature STE emission to more complex coupling to several phonon modes with out-of-plane components. Thereby, a unique view is provided into the lattice deformations and recombination dynamics that are key to designing more efficient materials.

Published
2022

95. Mixed Dimethylammonium/Methylammonium Lead Halide Perovskite Crystals for Improved Structural Stability and Enhanced Photodetection

Author

Ray, Aniruddha, primary, Martín‐García, Beatriz, additional, Moliterni, Anna, additional, Casati, Nicola, additional, Boopathi, Karunakara Moorthy, additional, Spirito, Davide, additional, Goldoni, Luca, additional, Prato, Mirko, additional, Giacobbe, Carlotta, additional, Giannini, Cinzia, additional, Di Stasio, Francesco, additional, Krahne, Roman, additional, Manna, Liberato, additional, and Abdelhady, Ahmed L., additional

Published
2022
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