Review
Physics, Multidisciplinary
Zhi-Zhou Yu, Guo-Huan Xiong, Li-Fa Zhang
Summary: This review focuses on the importance of thermal management in nanoscale electronic devices, and discusses the applications of the NEGF method in phonon transport and thermoelectric transport studies. It explores the principles of phonon NEGF method in thermal transport in mesoscopic systems, as well as the effects of temperature gradient on charge, spin, and valley degrees of freedom in thermoelectric transport.
FRONTIERS OF PHYSICS
(2021)
Review
Physics, Condensed Matter
Yu-Jia Zeng, Zhong-Ke Ding, Hui Pan, Ye-Xin Feng, Ke-Qiu Chen
Summary: The phonon heat transport property in quantum devices has been of great interest due to its significant quantum behaviors. Efforts have been made in establishing theoretical methods for phonon heat transport simulation in nanostructures, with challenges remaining in modeling phonon heat transport from wavelike coherent regime to particlelike incoherent regime. Among various theoretical approaches, Non-equilibrium Green's function (NEGF) method has attracted wide attention for its ability to perform full quantum simulation.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Chenchen Song
Summary: This paper presents a state-averaged complete active space self-consistent field (SA-CASSCF) method in the AMOEBA polarizable water model for rigorous simulation of non-adiabatic molecular dynamics with nonequilibrium solvation effects. The method solves the molecular orbital and configuration interaction coefficients, and the induced dipoles on solvent atoms, by minimizing the state averaged energy. The method is implemented by partitioning the calculations of different terms between the quantum chemistry and molecular mechanics codes.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Ali Moulhim, Brijesh Tripathi, Manoj Kumar
Summary: Through non-equilibrium Green function formalism, we analyzed the electron transport characteristics of nanoelectronic devices by coupling a quantum dot to metallic electrodes, and discussed the relationship between current and quantum dot size, level width, and temperature using analytical approximations. Furthermore, we also studied the dependence of current on applied voltage to understand the behavior of dual-channel nano-devices.
Article
Physics, Condensed Matter
G. Tkachov
Summary: This paper proposes a formula for the two-particle transmission coefficient in Cooper-pair transport between multi-band normal and superconducting materials, providing a direct calculation of the two-particle current without the use of Andreev reflection. As an application, the paper demonstrates a low-field linear magnetoresistance effect for superconductors with an induced nonunitary order parameter. These findings offer a new approach to detect unconventional nonunitary superconductivity in quantum materials of current interest.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Engineering, Electrical & Electronic
Vivekanand Shukla, Rameshwar L. Kumawat, Naresh K. Jena, Biswarup Pathak, Rajeev Ahuja
Summary: In this study, electron transport in bilayer phosphorene was investigated using first-principles and nonequilibrium Green's function formalism. The results showed that substitutional doping can tune the anisotropic nature of phosphorene and play a crucial role in interlayer current with rectifying behavior. Additionally, Fano resonance was observed, indicating potential applications in electronic devices.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Review
Thermodynamics
Carlos A. Polanco
Summary: Recent advances in fabrication techniques have enabled the development of materials sculpted at the nanoscale, revolutionizing thermal management technologies. Atomistic simulations are crucial for understanding dynamics on an atomic level, with nonequilibrium Green's functions (NEGF) simulations focusing on vibrational energy propagation. NEGF methodology, whether including harmonic interatomic potentials (h-NEGF) or anharmonic terms (a-NEGF), presents challenges and potential for quantum mechanical description of thermal transport.
NANOSCALE AND MICROSCALE THERMOPHYSICAL ENGINEERING
(2021)
Article
Nanoscience & Nanotechnology
Sayedreza Safdari, Morteza Soltani, Gholamreza Rashedi
Summary: We studied a 5-terminal system consisting of three single level quantum dots in contact with their respective reservoirs. In addition to the intra-dot Coulomb interaction, the electron in one dot is affected by an inter-dot Coulomb repulsion from its adjacent dot. Using the Anderson type model Hamiltonian and Greens function method, we investigated the transport properties of the system. Numerical analysis revealed a correlation between the transport characteristics of the lower and upper dot, which can be controlled by varying the parameters of the upper dot. We also found that the inter-dot Coulomb interaction improves the thermoelectric performance of the system.
Article
Nanoscience & Nanotechnology
Amir Taghavi Motlagh, Hojjatollah K. Salehani
Summary: A binary full adder circuit with eight quantum rings is designed, and its current-voltage characteristics are controlled by applying different gate voltages.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2022)
Article
Engineering, Electrical & Electronic
Preslav Aleksandrov, Ali Rezaei, Tapas Dutta, Nikolas Xeni, Asen Asenov, Vihar Georgiev
Summary: This work presents a new simulation approach called ML-NEGF that combines machine learning and device modeling simulations. The method utilizes quantum mechanical nonequilibrium Green's function approach for device simulations and extends a convolutional generative network for machine learning. The results demonstrate faster convergence speed of the ML-NEGF method compared to the standard NEGF approach, achieving an average speedup of 60% while maintaining accuracy.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Physical
Arseny Kovyrshin, Marten Skogh, Lars Tornberg, Anders Broo, Stefano Mensa, Emre Sahin, Benjamin C. B. Symons, Jason Crain, Ivano Tavernelli
Summary: This article discusses the application of coupled quantum electron-nuclear dynamics in the Born-Huang expansion of the molecular wave function and the perturbation of nonadiabatic effects. Meanwhile, a quantum algorithm for simulating the time evolution of molecular systems is proposed and applied to the proton transfer dynamics in malonaldehyde. The proposed algorithm can be easily extended to include the dynamics of the classically described molecular scaffold. If the electrons do not adiabatically follow the nuclear displacement, the entanglement between electronic and nuclear degrees of freedom can persist for a long time. When powerful quantum computers become available, the proposed algorithm may become a valid candidate for studying such phenomena.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Pablo Carpio-Martinez, Gabriel Hanna
Summary: This study investigates the effects of sampling the initial conditions of thermal baths from quantum and classical distributions on steady-state heat currents in the nonequilibrium spin-boson model. It finds that the heat currents are typically larger with classical bath sampling than with quantum bath sampling, with different temperature dependencies in different parameter regimes. The research highlights the importance of quantum bath sampling in quantum-classical dynamics simulations of quantum heat transport.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
C. Kaspar, A. Erpenbeck, J. Baetge, C. Schinabeck, M. Thoss
Summary: The interaction between electronic and vibrational degrees of freedom has a significant impact on electron transport in molecular nanostructures, especially for nonadiabatic coupling scenarios. The study employs the numerically exact hierarchical equations of motion approach to analyze the effects and reveals a variety of interesting transport phenomena.
Article
Physics, Multidisciplinary
Lei Zhang, Fuming Xu, Jian Chen, Yanxia Xing, Jian Wang
Summary: This paper presents a quantum nonlinear theory based on nonequilibrium Green's function (NEGF) for studying time-dependent ac transport properties in the low frequency and nonlinear bias voltage regimes. The theory satisfies current conservation and gauge invariance and allows for evaluation of nonlinear ac current at arbitrarily large bias voltages under the low frequency limit. The paper also derives the expression of time-dependent current under the wide band limit and establishes the relation between nonlinear electrochemical capacitance and bias voltage, providing valuable insights into the dynamical properties of nanoelectronic devices.
NEW JOURNAL OF PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Guoqing Zhou, Gang Lu, Oleg Prezhdo
Summary: Auger-type energy exchange is crucial in nanomaterials due to strong carrier-carrier interactions. A new ab initio technique was developed to accurately model Auger scattering with nonadiabatic molecular dynamics, describing charge-charge and charge-phonon scattering in a nonperturbative manner. This technique successfully reproduced experimental processes, providing detailed insights into carrier dynamics in nanomaterials with strong carrier-carrier interactions.
Article
Physics, Condensed Matter
Julian A. Lawn, Daniel S. Kosov
EUROPEAN PHYSICAL JOURNAL B
(2019)
Article
Chemistry, Physical
Riley J. Preston, Thomas D. Honeychurch, Daniel S. Kosov
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Vincent F. Kershaw, Daniel S. Kosov
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Maxim F. Gelin, Daniel S. Kosov
Summary: This paper proposes a model that includes the dynamical effects of solvent-molecule interaction in non-equilibrium Green's function calculations of the electric current, solving the electron transport properties of molecular junctions. Experimental results demonstrate that alignment of the rotating dipole moment can be used to break the particle-hole symmetry of the transmission and control the direction of the electric current.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Riley J. Preston, Maxim F. Gelin, Daniel S. Kosov
Summary: Theoretical frameworks combining various methods were utilized in this study to develop a reaction-rate theory for current-activated chemical reactions, which was later applied to different transport scenarios. The natural emergence of Landauer's blowtorch effect was demonstrated as a result of the interplay between configuration-dependent viscosity and diffusion coefficients, with localized heating and bond deformations due to current-induced forces being determining factors in chemical reaction rates within the system.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Riley J. J. Preston, Daniel S. S. Kosov
Summary: We propose a model for a molecular motor in a molecular electronic junction driven by Landauer's blowtorch effect. The effect arises from the interplay of electronic friction and diffusion coefficients, both calculated quantum mechanically using nonequilibrium Green's functions, within a semiclassical Langevin description of rotational dynamics. Numerical simulations demonstrate the motor's directional preference based on the intrinsic geometry of the molecular configuration. The proposed mechanism is expected to be applicable to various molecular geometries.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Thomas D. Honeychurch, Daniel S. Kosov
Summary: We investigate the effects of alternating voltage on nonequilibrium quantum systems with localized phonon modes using the Floquet approach. It was found that inelastic transport gained photon-assisted peaks and driving the alternating current at resonance with vibrational frequencies caused an increase in phonon occupation. The simplistic model proposed showed good agreement with the full model in certain parameter ranges.
Article
Materials Science, Multidisciplinary
Riley J. Preston, Thomas D. Honeychurch, Daniel S. Kosov
Summary: This study analyzes the effects of current-induced forces on molecular structures, with a focus on negative viscosities. The results show that negative viscosities can emerge not only in perturbative treatment but also in Ehrenfest dynamics. Additionally, the validity of the white-noise approximation for stochastic forces is assessed. The method is demonstrated using molecular junction models.
Article
Chemistry, Multidisciplinary
Jeffrey R. Reimers, Junhao Yang, Nadim Darwish, Daniel S. Kosov
Summary: In 2020, silicon-molecule-silicon junctions were found to be less conductive on average compared to traditional gold electrode junctions, but in some cases more conductive, with better extendability and mechanical stability. Calculations showed that these silicon-molecule-silicon junctions have extraordinary single-molecule conductivity due to the presence of unterminated silicon surface dangling bonds. The technology, explored through calculations and experiments, holds potential for numerous applications in electronics, nanotechnology, photonics, and sensing.
Article
Materials Science, Multidisciplinary
Samuel L. Rudge, Daniel S. Kosov
Summary: This paper investigates the waiting time distribution characteristics of triple quantum dots in different transport modes through calculating fluctuating-time statistics, revealing that the waiting time distribution displays coherent oscillations correlated with time and that quantum coherent effects introduce correlations between waiting times.
Article
Materials Science, Multidisciplinary
Nicholas S. Davis, Samuel L. Rudge, Daniel S. Kosov
Summary: This paper investigates the statistical behavior of electron transport through a molecular spin valve, demonstrating that different behaviors such as Poisson behavior, bunching, antibunching, and positive and negative temporal correlations can be achieved by tuning parameters. The study finds that strong positive temporal correlations emerge in the voltage range where the second transport channel is partially open, due to spin-induced electron bunching.
Article
Materials Science, Multidisciplinary
Thomas D. Honeychurch, Daniel S. Kosov
Article
Chemistry, Multidisciplinary
Chandramalika R. Peiris, Simone Ciampi, Essam M. Dief, Jinyang Zhang, Peter J. Canfield, Anton P. Le Brun, Daniel S. Kosov, Jeffrey R. Reimers, Nadim Darwish
Article
Materials Science, Multidisciplinary
Riley J. Preston, Vincent F. Kershaw, Daniel S. Kosov
Article
Materials Science, Multidisciplinary
Samuel L. Rudge, Daniel S. Kosov
