Review
Chemistry, Multidisciplinary
Shenghan Zhou, Ke Chen, Matthew Thomas Cole, Zhenjun Li, Mo Li, Jun Chen, Christoph Lienau, Chi Li, Qing Dai
Summary: The search for higher frequency information processing has led to intense research in micro, nano, and optoelectronics, with electron tunneling devices offering significantly faster response times compared to conventional semiconductor devices. This enhanced performance is driving the reimagination of traditional electronic devices and the emergence of new lightwave electronics. The current state-of-the-art, challenges, and opportunities in electron tunneling devices are reviewed, alongside potential future research directions in this rapidly advancing field.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Alexander S. Frolov, Carolien Callaert, Maria Batuk, Joke Hadermann, Andrey A. Volykhov, Anna P. Sirotina, Matteo Amati, Luca Gregoratti, Lada Yashina
Summary: This study investigates the reaction between the GeTe (111) surface with molecular oxygen, focusing on crystals with sole inversion domains. The reaction kinetics and structure of the oxide layer are evaluated, revealing nanoscale phase separation of GeO2 and Te, which is unusual for semiconductors.
Article
Chemistry, Multidisciplinary
Maximilian Ochs, Luka Zurak, Enno Krauss, Jessica Meier, Monika Emmerling, Rene Kullock, Bert Hecht
Summary: This study demonstrates the selective electrical excitation of symmetric and antisymmetric plasmonic modes in a two-wire transmission line. Mode selectivity is achieved by precisely positioning nanoscale excitation sources. The resulting device represents the smallest electrically driven light source with directly switchable polarization states.
Article
Chemistry, Multidisciplinary
Rocio Sanchez-de-Armas, Nicolas Montenegro-Pohlhammer, Aysegul Develioglu, Enrique Burzuri, Carmen J. Calzado
Summary: This study investigates the integration of SCO molecules on active nanodevices through quantum chemistry calculations, focusing on the encapsulation of Fe(ii) spin-crossover complexes in single-walled carbon nanotubes. The research reveals that the applied external electric field affects the spin-transition, and the local conditions of the substrate impact the transport properties.
Article
Multidisciplinary Sciences
Fabio Novelli, Kaixuan Chen, Adrian Buchmann, Thorsten Ockelmann, Claudius Hoberg, Teresa Head-Gordon, Martina Havenith
Summary: The study investigates the photo-induced radiolysis of water using an optical-pump terahertz-probe spectroscopy setup, revealing three distinct spectral responses. These responses correspond to the initial diffuse electron, the mass rearrangement of solvent molecules, and the weakening of the solvent cage characterized by the localized electron.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Multidisciplinary
Siyu Chen, Wenlu Shi, W. Ho
Summary: We demonstrate rectification spectroscopy (RS) for single molecules using continuous-wave terahertz (CW THz) radiation at the tunneling junction of a scanning tunneling microscope (STM) at 8 K. CW THz-RS offers a new technique for studying single-molecule vibrational and magnetic excitation spectroscopy, alongside inelastic electron tunneling spectroscopy (IETS). By comparing IETS and THz RS, we find that CW THz induces a sinusoidal bias modulation with an amplitude that is linearly dependent on the THz far-field amplitude. This THz-induced bias modulation amplitude appears to be sensitive to the alignment of the THz beam but insensitive to changes in the tunneling gap smaller than the THz wavelength.
Article
Nanoscience & Nanotechnology
Delphine Pommier, Zeilie Hufschmitt, Cheng Zhang, Yunhe Lai, Geirald Dujardin, Eric Le Moal, Christophe Sauvan, Jean-Jacques Greffet, Jianfang Wang, Elizabeth Boer-Duchemin
Summary: Quantum tunneling-driven optical nanoantennas play a vital role in the development of integrated plasmonic nanodevices. In this study, a tunneling junction between a nanoantenna and a thin gold film is used to electrically excite surface plasmons on the nanoscale. By employing an atomic force microscope, a novel method for completing the electrical circuit between the nanoantenna and the gold film is developed. Numerical modeling identifies the hybridized gap and antenna modes as the major contributors to the excitation of propagating surface plasmon polaritons.
Article
Chemistry, Multidisciplinary
Jiang Yao, Peter J. Wagner, Yunpeng Xia, Gregory Czap, W. Ho
Summary: This article introduces the study of DC current generation and its connection with inelastic electron tunneling spectroscopy and microscopy. The research found that although both techniques involve nonlinear features, there are significant differences in line shape analysis, which provides two complementary techniques for probing nanoscale systems.
Article
Chemistry, Multidisciplinary
Alexander Mehler, Nicolas Neel, Elena Voloshina, Yuriy Dedkov, Jorg Kroger
Summary: The study demonstrates the growth of graphene on h-BN through thermal decomposition and catalytic assistance of metal substrates, as well as the epitaxial growth of h-BN on Pt(111). Different honeycomb structures of graphene on h-BN and the observation of distinct superstructures at small probe-surface distances are highlighted in this study.
Article
Chemistry, Physical
A. Godard Palluet, F. Thibault, F. Lique
Summary: This study provides a new potential energy surface (PES) of the CO2-He van der Waals complex calculated with the coupled-cluster method and a complete basis set extrapolation, aiming to provide accurate rotational rate coefficients. The accuracy of the PES was tested through calculations of bound state transition frequencies and pressure broadening coefficients, showing excellent agreement with experimental data. Revised collisional data for the 10-300 K temperature range were provided, with rate coefficients found to be up to 50% greater than previously computed ones, potentially impacting the modeling of CO2 abundance in astrophysical media.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
A. Godard Paluet, F. Thibault, F. Lique
Summary: The CO2-He van der Waals complex has been studied with a new potential energy surface (PES) calculated using the coupled-cluster method and a complete basis set extrapolation. The accuracy of the PES was tested through bound state transition frequencies and pressure broadening coefficients, showing excellent agreement with experimental data. Revised collisional data for the 10-300K temperature range were provided, with rate coefficients found to be up to 50% greater than previously computed ones.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Shankar Kesarwani, Shobhna Misra, Dipankar Saha, Maria Luisa Della Rocca, Indrajit Roy, Swaroop Ganguly, Ashutosh Mahajan
Summary: In this paper, a noise-filtering algorithm based on Tikhonov Regularization is proposed for extracting IET spectra from measured DC I-V curves. By applying this algorithm to experimental data, it is demonstrated that the computed derivatives match well with the measured values, and the computed IET spectral peaks correlate with the experimental results.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Anna Kuzmina, Markus Parzefall, Patrick Back, Takashi Taniguchi, Kenji Watanabe, Achint Jain, Lukas Novotny
Summary: By controlled stacking of graphene layers, the limitation of single-layer graphene as a material for light-emitting devices has been overcome, enabling twist-controlled resonant light emission. Experimental findings show light emission irrespective of the crystallographic alignment between the graphene electrodes, with a spectrally tunable resonant peak in the near-infrared range.
Article
Chemistry, Multidisciplinary
Prosper Ngabonziza, Yi Wang, Peter A. van Aken, Joachim Maier, Jochen Mannhart
Summary: Researchers have developed high-temperature-stable tunnel junctions for inelastic tunneling spectroscopy studies above room temperature. By analyzing the vibrational modes of O-H bonds in BaZrO3-based heterostructures, they achieved proton detection with a spectral resolution of 20 meV at 400 K, overturning previous predictions. This breakthrough enables high-temperature tunneling spectroscopy of ion conductors, making it a novel and valuable analytical tool for solid-state ionics.
ADVANCED MATERIALS
(2021)
Article
Computer Science, Interdisciplinary Applications
Anup Kumar Mandia, Bhaskaran Muralidharan, Jung-Hae Choi, Seung-Cheol Lee, Satadeep Bhattacharjee
Summary: The module calculates the mobility and conductivity of semiconducting materials using Rode's algorithm with good agreement to experimental results, and shows favorable improvement compared to the RTA method.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Heesoo Park, Syam R. Kumar, Akinlolu Akande, Stefano Sanvito, Fedwa El-Mellouhi
Summary: Niobates, tantalates, and bismuthates have shown potential as substitutes for lead-halide perovskites in photonics and energy-harvesting applications. In this study, first-principles materials design was used to investigate the electrochemical potential of certain Nb-, Ta-, and Bi-based oxides/chalcogenides. The analysis revealed that some compounds exhibited reduced electronic dimensionality despite their higher structural dimensionality. The computational results indicated that certain Bi-based chalcogenides, namely KBiO2 and KBiS2, showed efficient photocatalytic performance under various pH conditions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Electrical & Electronic
Seongcheol Noh, Stefano Sanvito, Mincheol Shin
Summary: This study investigates the biaxial strain effects of Co2FeAl-based magnetic tunnel junctions (MTJs). The results show that the FeAl-O interfaced MTJ exhibits a converged tunneling magnetoresistance (TMR) ratio under compressive strain, while the Co-2-O interfaced MTJ shows a strain-sensitive TMR ratio under both compressive and tensile strain.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Review
Chemistry, Multidisciplinary
Alessandro Lunghi, Stefano Sanvito
Summary: This article describes how advanced computational methods and data-driven approaches to materials modeling can be used to design magnetic molecules and achieve control and preservation of spin.
NATURE REVIEWS CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Cheng Tang, Lei Zhang, Stefano Sanvito, Aijun Du
Summary: A general strategy for achieving 2D triferroicity by imposing electric polarization into a ferroelastic magnet is proposed in this study, and dual transition-metal dichalcogenides, such as 1T'-CrCoS4, are demonstrated to display room temperature triferroicity. The 1T'-CrCoS4 monolayer shows negative out-of-plane piezoelectricity and strain-tunable magnetic anisotropy, making it a strong candidate for practical applications. This research introduces a new class of 2D room-temperature triferroic materials, providing a promising platform for advanced spintronics.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Yuxuan Jiang, Shi Li, Yudi Wang, Haoyang Pan, Yongfeng Wang, Stefano Sanvito, Shimin Hou
Summary: The retention of open-shell character of organic radicals in contact with metal electrodes is crucial for their applications in molecular electronic devices. By using first-principles quantum transport calculations, the stability and electronic transport properties of single-molecule junctions incorporating a Blatter radical (BR) have been investigated. The calculations show that the BR can retain its open-shell nature even when bound to gold electrodes through undercoordinated gold adatoms, and the conductance values of junctions with BR are in agreement with experimental measurements. This study deepens the understanding of radical-metal interfacial properties and aids in the design of radical-based molecular devices.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Bruno Focassio, Michelangelo Domina, Urvesh Patil, Adalberto Fazzio, Stefano Sanvito
Summary: Kohn-Sham density functional theory (KS-DFT) is a powerful method used to obtain important material properties, but the computational costs associated with solving the KS equations limit its application to complex systems. To overcome this, machine learning (ML) models can be employed as surrogates to accurately predict the converged DFT charge density, allowing for faster and more cost-effective computations.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Computer Science, Artificial Intelligence
Laura Gambini, Tiarnan Mullarkey, Lewys Jones, Stefano Sanvito
Summary: High-resolution electron microscopy requires a high electron dose, which can damage the specimen and affect observation. Our work utilizes machine learning to improve the quality of Scanning Transmission Electron Microscope images generated at low electron dose, effectively reducing noise levels and approaching ground-truth precision.
MACHINE LEARNING-SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Applied
Joshua F. Belot, Valentin Taufour, Stefano Sanvito, Gus L. W. Hart
Summary: Researchers developed machine-learning models based on the chemical composition of materials to predict Curie temperatures. A random-forest model provided the most accurate predictions and did not require dimensionality reduction or complex descriptors. Cobalt-rich and iron-rich materials showed the highest Curie temperatures among binary and ternary compounds.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Rui Dong, Alessandro Lunghi, Stefano Sanvito
Summary: This study uses chemically accurate ab initio machine learning force fields in molecular dynamics simulations to investigate the effect of layer stiffness on the superlubricant state of two-dimensional van der Waals heterostructures. It is found that increasing the intralayer stiffness leads to a significant reduction in friction. Two sliding regimes, characterized by different heat exchange and temperature profiles, are observed at different sliding velocities.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Yudi Wang, Haoyang Pan, Dongying Lin, Shi Li, Yongfeng Wang, Stefano Sanvito, Shimin Hou
Summary: In molecular electronics, electrode-molecule anchoring strategies are crucial in the design of stable and high-performance functional single-molecule devices. In this study, we used aromatic pyrazine as anchors to connect a central anthracene molecule to carbon electrodes, and investigated their atomic structures and electronic transport properties theoretically. The pyrazine anchors facilitated the formation of stable and well-defined molecular junctions, and could also modulate the polarity of charge carriers in carbon-electrode molecular electronic devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Jacopo Simoni, Stefano Sanvito
Summary: The total angular momentum of a closed system should remain constant in time, but it is not satisfied in real-time simulations. The simplified description of spin-orbit coupling neglects the contribution of itinerant electrons. The conservation can be reintroduced through proper choice of spin-orbit coupling.
Article
Materials Science, Multidisciplinary
Matteo Cobelli, Paddy Cahalane, Stefano Sanvito
Summary: In this paper, an optimization method is presented to invert the local many-body descriptors of the chemical environment back to a Cartesian representation. This enables finding the Cartesian representation of known structure variations. The algorithm, implemented with the bispectrum representation, is demonstrated for molecules with different bonding structures and atomic species, making it a convenient approach for constructing structural generative models.
Article
Materials Science, Multidisciplinary
James Nelson, Luuk Coopmans, Graham Kells, Stefano Sanvito
Summary: We investigate the potential of supervised machine learning to propagate a quantum system in time. We find that for non-Markovian systems, their description requires the memory knowledge of past states, and the number of past states required grows exponentially with the number of spins and with the density of the system spectrum. Additionally, we demonstrate that neural networks can work as time propagators and can be concatenated in time to form an autoregression.
Article
Materials Science, Multidisciplinary
M. Domina, M. Cobelli, S. Sanvito
Summary: This paper introduces a method for representing vector fields with translational and rotational invariance, which can be utilized in the construction of machine learning energy models for solids and molecules. The method allows for the description of energy fluctuations due to atomic motion, longitudinal and transverse excitations of the vector field, and their interactions. The method can be applied to physical systems where the total energy is determined by a vector density.
Article
Materials Science, Multidisciplinary
Gokaran Shukla, Stefano Sanvito, Geunsik Lee
Summary: This study explores the potential of AlN and ZnO as insulating barrier materials in magnetic tunnel junctions. The experimental results show that AlN and ZnO have band structures suitable for spin filtering, which may result in a large tunneling magnetoresistance.
