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
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
Materials Science, Multidisciplinary
Xiao Wan, Dengke Ma, Dongkai Pan, Lina Yang, Nuo Yang
Summary: In this study, phonon transport optimization in graphene nanoribbon was achieved by designing nanopillared nanostructures based on resonance hybridization. It was found that thermal conductance decreases non-monotonically with an increase in the number of nanopillared structures, blocking phonon transport. Insights into controlling phonon transport in nanostructures were provided through mode-analysis, calculations, and simulations.
MATERIALS TODAY PHYSICS
(2021)
Article
Physics, Multidisciplinary
Ding Jin-Ting, Hu Pei-Jia, Guo Ai-Min
Summary: In this study, the electron transport in disordered zigzag graphene nanoribbons (ZGNRs) with three types of line defects is investigated theoretically. It is found that although there are localized electronic states around the Fermi energy in disordered ZGNRs with randomly distributed line defects, a transmission gap appears around the Fermi energy. The size of the transmission gap strongly depends on the type of disorder, disorder degree, and width of the nanoribbon.
ACTA PHYSICA SINICA
(2023)
Article
Physics, Multidisciplinary
L. Du, C. D. Ren, L. Cui, W. T. Lu, H. Y. Tian, S. K. Wang
Summary: This paper theoretically investigates the manipulation of valley-polarized currents and the optical-like behaviors of Dirac fermions in graphene with a single line defect. The introduction of a local uniaxial strain increases the valley transmission probability and results in the emergence of transmission plateau in a large angle range. The research findings suggest that perfect valley polarization can occur in a larger incident angle range compared to solely line defect, even in the presence of Anderson disorder.
Article
Physics, Applied
Moslem Zare, Reza Asgari
Summary: The effects of vacancy defects on the electronic and magnetic properties of zigzag graphene nanoribbons (zGNRs) were investigated, revealing significant changes in exchange coupling depending on the location and number of defects, as well as a new technique for probing local vacancies through RKKY exchange interactions.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Review
Nanoscience & Nanotechnology
Hongyu Tian, Chongdan Ren, Sake Wang
Summary: This article introduces the origin of the valley concept and the development of valleytronics, and discusses the influence of line defects in polycrystalline 2D materials on valley transport properties, as well as the methods and numerical simulation techniques for achieving valley polarization.
Article
Physics, Condensed Matter
Yazdan Soori, Hamed Rezania
Summary: In this study, the dynamical spin susceptibilities of biased bilayer graphene were investigated using Green's function approach, revealing the frequency dependence of imaginary part of spin susceptibilities and their dependence on spin polarization under different bias voltages. The position of sharp peaks in the frequency dependence introduces collective magnetic excitation modes of itinerant electrons in the bilayer system.
SOLID STATE COMMUNICATIONS
(2021)
Article
Nanoscience & Nanotechnology
Weidong Zheng, Connor J. McClellan, Eric Pop, Yee Kan Koh
Summary: In this study, accurate measurements of thermal boundary resistance (R) of 2D material interfaces were conducted. It was found that, in addition to phonon transport, thermal resistance between nonequilibrium phonons in the 2D materials could also play a critical role. These findings provide important insights into heat dissipation in 2D material devices and highlight the significance of considering the influence of nonequilibrium phonons in device design.
ACS APPLIED MATERIALS & INTERFACES
(2022)
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, Multidisciplinary
Chenxiaoyu Zhang, Shaobin Yang, Xu Zhang, Yingkai Xia, Jiarui Li
Summary: This paper investigates the CH4 adsorption properties of extended line defect (ELD) graphene modified by Mn atoms using density functional theory. The results show that the modified ELD graphene can enhance CH4 adsorption capacity.
Article
Physics, Multidisciplinary
Yi Guo, Peng Zhao, Gang Chen
Summary: The study examines the thermally-driven spin-dependent transport properties of a molecular junction using density functional theory and nonequilibrium Green function methodology. It demonstrates that magnetic field and light can regulate the currents effectively, leading to spin-filtering and thermal switching effects. Based on these properties, basic thermal spin molecular gates were designed.
Article
Nanoscience & Nanotechnology
M. Najarsadeghi, A. Ahmadi Fouladi, A. Zati Rostami, A. Pahlavan
Summary: Using the non-equilibrium Green's function method and tight-binding Hamiltonian model, the spin-dependent transport and tunnel magnetoresistance (TMR) of AAA- and ABC-stacked trilayer zigzag graphene nanoribbon (TLG) connected to two ferromagnetic (FM) single-layer zigzag graphene nanoribbons (FM/TLG/FM system) were theoretically investigated. Results showed that the TMR for both AAA- and ABC-stacked cases could be increased about 100% due to the band-selective rule, and the magnitude of this 100% TMR region enhanced with the increase of the magnetization strength in FM graphene nanoribbon electrodes. The TLG dimension also had a prominent effect on the TMR ratio of the system.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2022)
Article
Nanoscience & Nanotechnology
M. W. Chuan, S. Z. Lok, A. Hamzah, N. E. Alias, S. Mohamed Sultan, C. S. Lim, M. L. P. Tan
Summary: Due to the scaling down of transistor node technology, the effect of Stone-Wales defects on the electronic properties of graphene nanoribbons (GNRs) was examined. The results showed that Stone-Wales defects caused fluctuation in the band structure and increased the bandgap values for both armchair GNRs (AGNRs) and zigzag GNRs (ZGNRs) at every simulated width. In addition, Stone-Wales defects reduced the numerical computation density of states (DOS) for both AGNRs and ZGNRs, but their significance decreased with increasing structure length.
ADVANCES IN NANO RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
V Ryzhii, M. Ryzhii, T. Otsuji, V Mitin, M. S. Shur
Summary: The study found significant differences in the heat capacity of quasi-non-equilibrium two-dimensional electron-hole plasmas in graphene layers and graphene bilayers, which may be useful for the optimization of high-speed devices.
