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Here, we introduce the synthesis and deposition of organic/inorganic composite ink on cellulose paper using a rapid ultrasonic spray deposition approach that can be incorporated as a counter electrode (CE) in flexible dye-sensitized solar cells (FDSSCs). The composite ink comprised a copper indium sulfide (CuInS2) nanostructure ink and dispersion of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) in water. Fabricated counter electrodes are biodegradable, environment-friendly, flexible, and economical and meet the requirements for sustainable green energy. To evaluate the catalytic activities and power conversion efficiencies of DSSCs, the produced CuInS2/PEDOT:PSS composite ink-based CEs were compared with PEDOT:PSS counter electrodes. Cyclic voltammetry studies found that CuInS2/PEDOT:PSS had a greater cathodic charge transfer current density (Jc) (−1.23 mA cm−2). Moreover, it was found that the potential separation values are small, which indicate a stronger catalytic activity than PEDOT:PSS counter electrodes. The observed exchange current density (J0) was 3.98 mA cm−2, while the limiting current density (Jlim) increased to 45.7 mA cm−2, indicating a fast redox diffusion rate of the CuInS2/PEDOT:PSS CE. The photovoltaic performances of CuInS2/PEDOT:PSS and PEDOT: PSS-based DSSC's were measured and determined to be 5.66% and 4.41%, respectively, while the performance of CuInS2/PEDOT:PSS FDSSC composed of cellulose paper was 1.06%. [ABSTRACT FROM AUTHOR]

Paper-based devices have recently emerged as simple and low-cost paradigms for fluid manipulation and analytical/clinical testing. However, there are significant challenges in developing paper-based devices at the system level, which contain integrated paper-based power sources. Here, we report a microfabricated paper-based bacteria-powered battery that is capable of generating power from microbial metabolism. The battery on paper showed a very short start-up time relative to conventional microbial fuel cells (MFCs); paper substrates eliminated the time traditional MFCs required to accumulate and acclimate bacteria on the anode. Only four batteries connected in series provided desired values of current and potential to power an LED for more than 30 minutes. The battery featured (i) a low-cost paper-based proton exchange membrane directly patterned on commercially available parchment paper and (ii) paper reservoirs for holding the anolyte and the catholyte for an extended period of time. Based on this concept, we also demonstrate the use of paper-based test platforms for the rapid characterization of electricity-generating bacteria. This paper-based microbial screening tool does not require external pumps/tubings and represents the most rapid test platform (＜50 min) compared with the time needed by using traditional screening tools (up to 103 days) and even recently proposed MEMS arrays (＜ 2 days). [ABSTRACT FROM AUTHOR]

Surface enhanced Raman spectroscopy (SERS) is a highly sensitive technique for the non- or minimally invasive identification of molecules at very low concentrations. In this work, SERS is exploited using naked laser-ablated gold nanoparticles (AuNPs) for the detection of dyes on artificially aged paper inked with a ballpoint pen. Although several studies on inks with SERS are present in the literature, most of them report on the investigations on freshly prepared products, and less information is present on the detection of aged dyes and inks using SERS. Ballpoint inks are commonly used in daily activities, but have also been employed by several contemporary artists. These inks are very sensitive to light, and they discolor rapidly, making their detection demanding. In the present work, the SERS spectra of a ballpoint pen ink on two types of paper were analyzed after light-induced ageing, and the importance of the dye–AuNP interaction is discussed. The results show that the interpretation of the SERS spectra of the aged samples, such as those of interest in the Cultural Heritage field, is a tricky and delicate operation and that the diffusion of the dyes to the hot spot regions of the plasmonic nanoparticles plays a pivotal role in the detection of degraded ink components. Therefore, appropriate evaluation of the factors affecting the molecule–plasmonic nanoparticle interactions and of the history of the artwork to be analyzed is fundamental to avoiding the misinterpretation of the spectra and, consequently, of the original composition of the analyzed artwork. [ABSTRACT FROM AUTHOR]

In this paper, we reported the synthesis and characterization of CoNiCuCrS nanoparticle alloys using scanning transmission electron microscopy (STEM) techniques. The nanoparticles form hexagonal platelets with an average size of 34.5 nm. Atomic resolution STEM imaging reveals an ordered FCC crystal structure with a lattice parameter of 0.93 nm, consistent with a (CuCo)6Ni3Cr1S13.333 intermetallic phase. The paper provided direct experimental evidence of the strain distribution at the atomic scale using advanced STEM techniques. The findings are consistent with previous studies, confirming the presence of small but significant strains in high entropy alloys (HEAs). By studying nanoparticles, we achieved atomic-resolution imaging and characterization, which is challenging with bulk HEA samples. The work revealed that defects like stacking faults and partial dislocations, stabilized by the presence of sulphur in our sample, play an important role in the mechanical properties of HEAs. This research demonstrated that nanoparticles can be used as a model for studying bulk properties of HEAs, providing insights into local strain effects and crystal growth dynamics. [ABSTRACT FROM AUTHOR]

A unique nanomaterial has been developed for sweat analysis, including glucose level monitoring. Simple resusable low-cost sensors from composite materials based on graphene, hexagonal boron nitride, and conductive PEDOT:PSS (poly(3,4-ethylenedioxythiophene)polystyrene sulfonate) polymer have been developed and fabricated via 2D printing on flexible substrates. The sensors were tested as biosensors using different water-based solutions. A strong increase in the current response (several orders of magnitude) was observed for aqua vapors or glucose solution vapors. This property is associated with the sorption capacity of graphene synthesized in a volume of plasma jets and thus having many active centers on the surface. The structure and properties of graphene synthesized in a plasma are different from those of graphene created by other methods. As a result, the current response for a wearable sensor is 3–5 orders of magnitude higher for the reference blood glucose concentration range of 4–14 mM. It has been found that the most promising sensor with the highest response was fabricated based on the graphene:PEDOT:PSS composite. The graphene:h-BN:PEDOT:PSS (h-BN is hexagonal boron nitride) sensors demonstrated a longer response and the highest response after the functionalization of the sensors with a glucose oxidase enzyme. The reusable wearable graphene:PEDOT:PSS glucose sensors on a paper substrate demonstrated a current response of 10−10 to 10−5 A for an operating voltage of 0.5 V and glucose range of 4–10 mM. [ABSTRACT FROM AUTHOR]

With the advent of the post-Moore's Law era, the development of traditional silicon-based computers has reached its limit, and there is an urgent need to develop new computing technologies to meet the needs of science, technology, and daily life. Due to its super-strong parallel computing capability and outstanding data storage capacity, DNA computing has become an important branch and hot research topic of new computer technology. DNA enzyme-free hybridization reaction technology is widely used in DNA computing, showing excellent performance in computing power and information processing. Studies have shown that DNA molecules not only have the computing function of electronic devices, but also exhibit certain human brain-like functions. In the field of artificial intelligence, activation functions play an important role as they enable artificial intelligence systems to fit and predict non-linear and complex variable relationships. Due to the difficulty of implementing activation functions in DNA computing, DNA circuits cannot easily achieve all the functions of artificial intelligence. DNA circuits need to rely on electronic computers to complete the training and learning process. Based on the parallel computing characteristics of DNA computing and the kinetic features of DNA molecule displacement reactions, this paper proposes a new activation function. This activation function can not only be easily implemented by DNA enzyme-free hybridization reaction reactions, but also has good nesting properties in DNA circuits, and can be cascaded with other DNA reactions to form a complete DNA circuit. This paper not only provides the mathematical analysis of the proposed activation function, but also provides a detailed analysis of its kinetic features. The activation function is then nested into a nonlinear neural network for DNA computing. This system is capable of fitting and predicting a certain nonlinear function. [ABSTRACT FROM AUTHOR]

In this paper, we innovatively stack multiple resonant units of photoconductive silicon to design an ultra-broadband metamaterial absorber. By manipulating the conductivity of the silicon with a pump beam, adjustments are made to the amplitude of the wide absorption spectrum spanning 6.6 THz, enabling functional switching from total reflection to near-perfect ultra-broadband absorption. By integrating vanadium dioxide as an intermediary layer, a dual-mode switchable absorber is realized, offering dual control functionalities. Temperature changes enable the absorber to switch between dual-band absorption and ultra-broadband absorption, while variations in pump beam intensity allow for further amplitude adjustments within the absorption spectrum. Impedance matching theory and near-field analysis provide the necessary physical foundation for understanding broadband absorption. Structural parameters, incident angle, and polarization angle of the incident electromagnetic waves are also studied to demonstrate the device's robustness. Our proposed absorbers not only greatly broaden the absorption bandwidth of silicon-based absorbers, but also offer versatility, polarization insensitivity, and robustness over a wide range of incidence angles. Moreover, our design ideas are useful for broadening the bandwidth and enhancing absorption, which enables wider applications in ultra-broadband terahertz absorption and promises extensive prospects. [ABSTRACT FROM AUTHOR]

Molecular transport maintains cellular structures and functions. For example, lipid and protein diffusion sculpts the dynamic shapes and structures on the cell membrane that perform essential cellular functions, such as cell signaling. Temperature variations in thermal equilibrium rapidly change molecular transport properties. The coefficient of lipid self-diffusion increases exponentially with temperature in thermal equilibrium, for example. Hence, maintaining cellular homeostasis through molecular transport is hard in thermal equilibrium in the noisy cellular environment, where temperatures can fluctuate widely due to local heat generation. In this paper, using both molecular and lattice-based modeling of membrane transport, we show that the presence of active transport originating from the cell's cytoskeleton can make the self-diffusion of the molecules on the membrane robust to temperature fluctuations. The resultant temperature-independence of self-diffusion keeps the precision of cellular signaling invariant over a broad range of ambient temperatures, allowing cells to make robust decisions. We have also found that the Kawasaki algorithm, the widely used model of lipid transport on lattices, predicts incorrect temperature dependence of lipid self-diffusion in equilibrium. We propose a new algorithm that correctly captures the equilibrium properties of lipid self-diffusion and reproduces experimental observations. [ABSTRACT FROM AUTHOR]

In the field of photothermal conversion, light-absorbing layers show limitations such as low solar energy utilization and excessive surface reflection. This paper proposes a new anti-reflective coating consisting of a gradient-doped fluorescent glass film covering a subwavelength structural layer for photothermal conversion. Its transmittance was simulated using equivalent medium theory and the admittance recursion method. The subwavelength structure provides a refractive index gradient, and its shape solves the problem of the sharp decrease in transmittance at high angles of incidence. Subsequently, we adjust the material parameters of the gradient refractive layers and control the thickness of each layer to minimize interlayer Fresnel reflections. Finally, the efficient light-trapping ability of the model was verified by calculating and comparing the transmittances of the optimized model and bare glass. Notably, within the visible spectrum, our model achieves an average transmittance of over 95% across wavelength and angle ranges, effectively suppressing surface reflections. At a larger light incident angle, the transmittance increases by 29.7%, and the minimum angle transmittance reaches 92.7%. This study proposes an innovative method to enhance the performance of transmission layers in photothermal conversion devices. [ABSTRACT FROM AUTHOR]

Correction for 'Optical absorption and shape transition in neutral SnN clusters with N ≤ 40: a photodissociation spectroscopy and electric beam deflection study' by Andreas Lehr et al., Phys. Chem. Chem. Phys., 2022, 24, 11616–11635, https://doi.org/10.1039/D2CP01171A. [ABSTRACT FROM AUTHOR]

Prospective composites, based on graphene (G) and hexagonal boron nitride (h-BN) nanoparticles, synthesized using a plasma jet and conducting polymer PEDOT:PSS, were used to create and study a set of sensors in the current study. The composites used were G:PEDOT:PSS (GPP) and G:h-BN:PEDOT:PSS (GBNPP). The PEDOT:PSS content in the composites was 10−3 wt%, and the ratio of G : h-BN was 1 : 1 in GBNPP. The development of these new highly conductive graphene-based composites makes it possible to create an active sensor layer with an ultra-low thickness of several nanometers. The ultra-high sensitivity of the current response, S, was ((2.0–3.3) × 106)% for GPP and GBNPP (2–3 printing layers) for a humidity range of 20–80%. The sensor response in the form of current pulses associated with human breathing has a range of ∼2–3 orders of magnitude. Two different processes are assumed to determine the form of the current pulse: the first is a fast process with a rise time of less than 1–4 seconds; the second is a relatively slow process with a front time of several tens of seconds. When touching with a finger (useful, for instance, for a flexible touchpad), a current response was observed as pulses of ∼2–3 orders of magnitude. We hypothesize that skin sweat is likely to play a critical role in the sensory response. Thus, this work presents an effective approach to creating a highly sensitive humidity sensor based on composite 2D materials. Moreover, the ultra-high sensitivity of the studied sensors is accompanied by their low cost and ease of manufacturing by 2D-printing. [ABSTRACT FROM AUTHOR]

In this paper, a novel type of tunable ultra-wide band and double-narrow band artificial electromagnetic absorption device is studied. This work uses a titanium nitride–titanium–tungsten (TiN–Ti–W) composite ring array, a TiN reflector layer, and a silver–titanium dioxide–silver (Ag–TiO2–Ag) three layer composite structure to prepare the absorption layer. The simulation results illustrate that the absorption rate can reach 96.6% when the absorption wavelength is 300–2800 nm. When the light source is backward incidence, ultra-narrow band absorption can occur at specific wavelengths of 465 nm and 932 nm. This proves that the absorber is in good agreement with the impedance matching theory. The research results of this work will provide a theoretical basis for the design and application of solar thermal energy conversion. [ABSTRACT FROM AUTHOR]

In this paper, we propose a borophene-based grating structure (BBGS) to realize multi-band plasmoninduced absorption. The coupling of two resonance modes excited by upper borophene grating (UBG) and lower borophene grating (LBG) leads to plasmon-induced absorption. The coupled-mode theory (CMT) is utilized to fit the absorption spectrum. The simulated spectrum fits well with the calculated result. We found the absorption peaks exhibit a blue shift with an increase in the carrier density of borophene grating. Further, as the coupling distance D increases, the first absorption peak shows a blue shift, while the second absorption peak exhibits a red shift, leading to a smaller reflection window. Moreover, the enhancement absorption effect caused by the bottom PEC layer is also analyzed. On this basis, using a three-layer borophene grating structure, we designed a three-band perfect absorber with intensities of 99.83%, 99.45%, and 99.96% in the near-infrared region. The effect of polarization angle and relaxation time on the absorption spectra is studied in detail. Although several plasmon-induced absorption based on two-dimensional (2D) materials, such as graphene, black phosphorus, and transition metal dichalcogenides (TMDs), have been previously reported, this paper proposes a borophene-based metamaterial to achieve plasmon-induced perfect absorption since borophene has some advantages such as high surface-to-volume ratios, mechanical compliance, high carrier mobility, excellent flexibility, and long-term stability. Therefore, the proposed borophene-based metamaterial will be beneficial in the fields of multi-band perfect absorber in the near future. [ABSTRACT FROM AUTHOR]

Due to overuse of plastic products, decomposed microplastics (MPs) are widely spread in aquatic ecosystems, and will cause irreparable harm to the human body through the food chain. Traditional MP detection methods require cumbersome sample pre-processing procedures and complex instruments, so there is an urgent demand to develop methods to achieve simple on-site detection. Herein, a simple, sensitive, accurate, and stable MP detection method based on surface-enhanced Raman scattering (SERS) is investigated. Considering the hydrophobic problems of MPs, gold nanoparticle (AuNP) doped filter paper as a flexible SERS substrate is applied to capture MPs in the fiber pores. Benefitting from the electromagnetic (EM) hot spots generated by AuNPs, the Raman signal of MPs can be effectively enhanced. Meanwhile, the flexible SERS substrate has good sensitivity to a minimum detectable concentration of 0.1 g L−1 for polyethylene terephthalate (PET) in water, and the maximum enhancement factor (EF) can reach 360.5. Furthermore, the practicability of the developed method has been proved by the successful detection of MPs in tap water and pond water. This research provides an easy process, high sensitivity, and good reproducibility method for MP detection. [ABSTRACT FROM AUTHOR]

In this paper, we design a solar absorber based on the Si3N4–W–Ti–SiO2 insulator–metal–insulator structure and demonstrate it using the finite difference time domain (FDTD) method. The absorption rate of the absorber consisting of a multi-layer structure with cross etching is over 90% in the bandwidth of 500 nm to 2995 nm with an average absorption rate of 98.3%. There are three peaks at 620 nm, 1002 nm and 1761 nm with peak heights of 99.8%, 99.8% and 99.0%, respectively. By analyzing the distribution of electric and magnetic fields in different sections of the absorber, it is found that the physical mechanism of the structure with high absorptivity is due to the interaction of propagating surface plasmon resonance and local surface plasma resonance. The effects of different structural parameters and the angle of incidence of a light source on the absorber absorption are discussed. The absorber can be used in solar thermal systems, thermal photovoltaics and thermoelectronic devices. [ABSTRACT FROM AUTHOR]

Porous liquids (PLs) are the combination of porous solid material and flowing liquid, which provides alternative options to solve difficulties in the development of porous solids. With the booming development of PLs since 2015, plenty of syntheses and applications have been reported with a specific focus on gas adsorption. Given the lack of a comprehensive review, this paper reviews the application of PLs in CO2 capture. To start with, ground-breaking case studies are reviewed to help understand the progress of PLs research. Then, as a major part of this paper, studies of PLs for CO2 capture are reviewed separately. Moreover, five basic properties of porous liquids, including stability, viscosity, selectivity, porosity, capacity, and the influencing factors are systemically reviewed respectively. Furthermore, gas storage and release mechanisms in PLs are briefly outlined, and potential processing methods of PLs used for CO2 capture are discussed. [ABSTRACT FROM AUTHOR]

Acetylcholine (Ach) is a common neurotransmitter in the central nervous system (CNS) and peripheral nervous system (PNS). It is one of the neurotransmitters in the autonomic nervous system and the main neurotransmitter in all autonomic ganglia. Experiments have confirmed that electromagnetic waves can affect the synthesis of animal neurotransmitters, but the microscopic effects of electromagnetic waves in the terahertz (THz) frequency band are still unclear. Based on density functional theory (DFT) and molecular dynamics (MD) simulation methods, this paper studies the effect of THz electromagnetic waves on the binding of choline to choline acetyltransferase (ChAT). By emitting THz waves that resonate with the characteristic vibration mode of choline near the active site, it was found that THz waves with a frequency of 45.3 THz affected the binding of choline to ChAT, especially the binding of the active site histidine His324 to choline. The main evidence is that under the action of THz waves, the binding free energy of choline to histidine His324 and ChAT at the active site was significantly reduced compared to noE, which may have a potential impact on the enzymatic synthesis of Ach. It is expected to achieve the purpose of regulating the synthesis of the neurotransmitter Ach under the action of THz waves and treat certain nervous system diseases. [ABSTRACT FROM AUTHOR]

In this paper, the optical and electron transport properties of the two-dimensional (2D) van der Waals (vdW) niobium oxide dichloride (NbOCl2) crystal with extremely high second-order nonlinear coefficients are investigated theoretically. We found that the strong absorption of NbOCl2 in the infrared region is caused by the indirect transition accompanied by phonons and confirmed that the interaction between layers is very weak. However, the study of electron transport properties shows that the interlayer interaction of NbOCl2 has a certain degree of influence on the scalability of electrical and optical properties. Because of the strong anisotropy of the NbOCl2 material, it will be a more optimized choice for constructing on-chip photoelectric or thermal devices in the Nb-Cl-Nb direction. [ABSTRACT FROM AUTHOR]

The study of energy correlations in catalytic reactions plays a pivotal role in guiding catalyst development. This paper focuses on the investigation of energy linear relationships in methanol synthesis from CO2 hydrogenation on copper surfaces, systematically exploring energy parameters including activation energy, reaction energy and adsorption energy. A comparative analysis of the adsorption characteristics and reaction parameters in the formate, formic acid and reverse water–gas shift pathways is conducted, laying the data foundation for subsequent linear studies. Then, descriptors are extracted from electronic, energetic and structural information and further integrated using the sure independence screening and sparsifying operator (SISSO) method to establish an energy description paradigm characterized by interpretability and accuracy. Additionally, reactions are further categorized based on hydrogenation types to mitigate the adverse effects of redundant data points. Finally, the summarized reaction descriptors are extended to Cu-based alloy systems to highlight the rationality and transferability of the developed descriptors. [ABSTRACT FROM AUTHOR]

In this paper, we undertake a theoretical investigation into the effects of both in-plane and out-of-plane static electric fields on moire' interlayer excitons (IXs) within a WSe2/MoSe2 heterobilayer. We thoroughly analyze a wide range of properties pertaining to the IXs, including the binding energy, Stark shift, orbital hybridization, photoluminescence (PL) spectra, and radiative lifetime. Various factors influencing IX behavior, such as the dielectric environment, spacing separation, and moire' trap effects, are examined in detail. Our results demonstrate that the in-plane electric field leads to energy splitting between states with non-zero angular momentum, such as the 2p± dark states. Consequently, we analyze IX orbital hybridization, including hybrid Rydberg states like 1s, 2p±, and 2s. In contrast, we show that an out-of-plane electric field induced by a double-gate setup causes a quadratic Stark effect on the center of mass (COM) eigenenergies, leading to energy splitting of degenerate states and resulting in orbital hybridization of COM eigenvectors. Additionally, we demonstrate that a parallel electric field brightens the 2p± dark state through a one-photon PL process, due to the hybridization phenomena between s- and p-type Rydberg states. In short, our investigation is in great agreement with previous research and can assist experimenters in designing novel optoelectronic applications, such as on-chip electro-optic modulators and TeraHertz devices. [ABSTRACT FROM AUTHOR]

While two-dimensional (2D) MoS2 has recently shown promise as a material for resistive random-access memory (RRAM) devices due to its demonstrated resistive switching (RS) characteristics, its practical application faces a significant challenge in industry regarding its limited yield and endurance. Our earlier work introduced an effective switching layer model to understand RS behavior in both mono- and multi-layered MoS2. However, functioning as a phenomenological percolation modeling tool, it lacks the capability to accurately simulate the intricate current–voltage (I–V) characteristics of the device, thereby hindering its practical applicability in 2D RRAM research. In contrast to the established conductive filament model for oxide-based RRAM, the RS mechanism in 2D RRAM remains elusive. This paper presents a novel simulator aimed at providing an intuitive, visual representation of the stochastic behaviors involved in the RS process of multi-layer 2D MoS2 RRAM devices. Building upon the previously proposed phenomenological simulator for 2D RRAM, users can now simulate both the I–V characteristics and the resistive switching behaviors of the RRAM devices. Through comparison with experimental data, it was observed that yield and endurance characteristics are linked to defect distributions in MoS2. [ABSTRACT FROM AUTHOR]

The Diósi–Penrose model states that the wave function collapse ending a quantum superposition occurs due to the instability of coexisting gravitational potentials created by distinct geometric conformations of the system in different states. The Heisenberg time-energy principle can be invoked to estimate the collapse time for the energy associated with this instability, the gravitational self-energy. This paper develops atomistic models to calculate the Diósi–Penrose collapse time. It applies them to a range of systems, from small molecules to large biological structures and macroscopic systems. An experiment is suggested to test the Diósi–Penrose hypothesis, and we critically examine the model, highlighting challenges from an atomistic perspective, such as gravitational self-energy saturation and limited extensivity. [ABSTRACT FROM AUTHOR]

In this paper, the electronic properties and transport characteristics of WSiGeN4/graphene heterostructures were explored by combining the quantum transport method with first-principle calculations. The band structures indicate that the heterostructures can form either p-type or n-type Schottky contacts, depending on the stacking mode. Due to the self-formed asymmetric Schottky contacts, we design an asymmetric van der Waals (vdW) metal–semiconductor–metal (MSM) structure, which exhibits a pronounced asymmetric current–voltage (I–V) curve. The corresponding physical mechanisms are attributed to carrier transport mechanisms, which are primarily governed by thermionic excitation at positive bias voltages and tunneling effects at negative bias voltages. Our study offers a viable strategy for integrating asymmetric Schottky barriers into MSM configurations, laying the groundwork for a wider range of applications in a range of Janus two-dimensional semiconductors. [ABSTRACT FROM AUTHOR]

A recently developed magnetic molecular interferometry technique allows the experimental determination of how the amplitudes and phases of the molecular wave-function change during the collision of a gas phase molecule with a surface. This information, quantified by a scattering-matrix, provides a very stringent benchmark for developing accurate theoretical models as they can also be determined from scattering calculations and are particularly sensitive to the underlying interaction potential. However, the value of this comparison is necessarily limited by the accuracy with which an empirical scattering-matrix can be extracted from the experimental data. This paper presents the methods used to analyse the measurements and uses simulations to determine how various uncertainties in modelling the different magnetic elements which make up the beamline of the apparatus affect the accuracy with which the scattering-matrix can be extracted. It is shown that when signals have a noise level which corresponds to on the order of 1% of the oscillation amplitude, the uncertainties in the modelling do not significantly affect the ability to extract the scattering-matrix elements, with the error in the extracted values increasing to a few percent as the noise in the signals is increased to 10% of the oscillation amplitude. This therefore gives an estimate of the accuracy of the parameters that can be obtained from future measurements. [ABSTRACT FROM AUTHOR]

Aromatic infrared bands (AIBs) dominate the mid-infrared spectra of many galactic and extragalactic sources. These AIBs are generally attributed to fluorescence emission from aromatic molecules. Unified efforts from experimentalists and theoreticians to assign these AIB features have recently received additional impetus with the launch of the James Webb Space Telescope (JWST) as the Mid-InfraRed Instrument (MIRI) delivers a mid-IR spectrum with greatly increased sensitivity and spectral resolution. PAHs in space can exist in either neutral or ionic form, absorb UV photons and undergo fragmentation, becoming a rich source of small hydrocarbons. This top-down mechanism of larger PAHs fragmenting into smaller species is of utmost importance in photo-dissociation regions (PDR) in space. In this work, we experimentally and theoretically investigate the photo-fragmentation pathways of two astronomically significant PAH cations – corannulene (C20H10) and sumanene (C21H12), which are structural motifs of fullerene C60, to understand their sequential fragmentation pathways. The photo-fragmentation experiments exhibit channels that are significantly different from planar PAHs. The breakdown of the carbon skeleton is found to follow different pathways for C20H10 and C21H12 because of the number and positioning of pentagon rings, yet the most abundant low mass cations produced by these two species are found to be similar. The low mass cations showcased in this work could be of interest due to their possible astronomical detections. For completeness, the qualitative photofragmentation behaviour of dicationic corannulene and sumanene has also been investigated, but the potential energy surface of these dications is beyond the scope of this paper. [ABSTRACT FROM AUTHOR]

Quantum spin liquids (QSLs) have become prominent materials of interest in the pursuit of fault-tolerant materials for quantum computing applications. This is due to the fact that these materials are theorized to host an interesting variety of quantum phenomena such as quasi-particles that may behave as anyons as a result of the high entangled nature of the spin states within the systems. Computing the electronic and magnetic properties of these materials is necessary in order to understand the underlying interactions of the materials. In this paper, the structural, electronic, and magnetic properties including lattice parameters, bandgap, Heisenberg coupling constants, and Curie temperatures for α-RuCl3, a promising candidate for the Kitaev QSL model, are computed using periodic density functional theory. Furthermore, various parameters of the calculations (i.e. functional choice, basis set, k-point density, and Hubbard correction) are varied in order to determine what effect, if any, the computational setup has on the computed properties. The results of this study indicate that PBE functional with Hubbard corrections of 1.5–2.5 eV with a k-point density of 3.0 points per Å−1 appear to be the best parameters to compute Heisenberg coupling constants for α-RuCl3. These parameters with the addition of spin orbit coupling works well for computing Curie temperatures for α-RuCl3. Distinct differences are noted in the computations of the bulk structure vs. monolayer structures, indicating that interactions between the layers play a role in the material properties and changes to the inter-layer spacing may result in interesting and unique magnetic properties that require further investigation. [ABSTRACT FROM AUTHOR]