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We apply the Wigner function formalism to derive drift-diffusion transport equations for spin-polarized electrons in a III-V semiconductor single quantum well. Electron spin dynamics is controlled by the linear in momentum spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Semion Saikin

We present a generally applicable parameter-free first-principles method to determine electronic spin relaxation times and apply it to the technologically important group-IV materials silicon, diamond and graphite. We concentrate on the…

Mesoscale and Nanoscale Physics · Physics 2012-09-19 Oscar D. Restrepo , Wolfgang Windl

Two drift-diffusion models for the quantum transport of electrons in graphene, which account for the spin degree of freedom, are derived from a spinorial Wigner equation with relaxation-time or mass- and spin-conserving matrix collision…

Mathematical Physics · Physics 2019-05-27 Nicola Zamponi , Ansgar Jüngel

Accurate determination of carrier transport properties in two-dimensional (2D) materials is critical for designing high-performance nano-electronic devices and quantum information platforms. While first-principles calculations effectively…

Mesoscale and Nanoscale Physics · Physics 2020-12-04 Sathwik Bharadwaj , Ashwin Ramasubramaniam , L. R. Ram-Mohan

Designing new quantum materials with long-lived electron spin states urgently requires a general theoretical formalism and computational technique to reliably predict intrinsic spin relaxation times. We present a new, accurate and universal…

Materials Science · Physics 2020-07-01 Junqing Xu , Adela Habib , Sushant Kumar , Feng Wu , Ravishankar Sundararaman , Yuan Ping

Spin fluctuations have a substantial influence on the electron and lattice behaviors in magnetic materials, which, however, is difficult to be tracked properly by prevalent first-principles methods. We propose a versatile self-adaptive…

Materials Science · Physics 2023-02-14 Zefeng Cai , Ke Wang , Yong Xu , Su-Huai Wei , Ben Xu

We study high-field spin transport of electrons in a quasi one-dimensional channel of a $GaAs$ gate controlled spin interferometer (SPINFET) using a semiclassical formalism (spin density matrix evolution coupled with Boltzmann transport…

Mesoscale and Nanoscale Physics · Physics 2009-09-29 S. Pramanik , S. bandyopadhyay , M. Cahay

First-principles calculations enable accurate predictions of electronic interactions and dynamics. However, computing the electron spin dynamics remains challenging. The spin-orbit interaction causes various dynamical phenomena that couple…

Materials Science · Physics 2022-11-04 Jinsoo Park , Yao Luo , Jin-Jian Zhou , Marco Bernardi

The classical drift diffusion (DD) model of spin transport treats spin relaxation via an empirical parameter known as the ``spin diffusion length''. According to this model, the ensemble averaged spin of electrons drifting and diffusing in…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Sandipan Pramanik , Supriyo Bandyopadhyay , Marc Cahay

The classical drift diffusion (DD) model of spin transport treats spin relaxation via an empirical parameter known as the ``spin diffusion length''. According to this model, the ensemble averaged spin of electrons drifting and diffusing in…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Sandipan Pramanik , Supriyo Bandyopadhyay , Marc Cahay

In this review we discuss the multifaceted problem of spin transport in hydrogenated graphene from a theoretical perspective. The current experimental findings suggest that hydrogenation can either increase or decrease spin lifetimes, which…

We report on spin transport features which are unique to high quality bilayer graphene, in absence of magnetic contaminants and strong intervalley mixing. The time-dependent spin polarization of propagating wavepacket is computed using an…

Mesoscale and Nanoscale Physics · Physics 2016-07-20 Dinh Van Tuan , Shaffique Adam , Stephan Roche

Spin transport experiments in graphene, a single layer of carbon atoms, indicate spin relaxation times that are significantly shorter than the theoretical predictions. We investigate experimentally whether these short spin relaxation times…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 M. Popinciuc , C. Józsa , P. J. Zomer , N. Tombros , A. Veligura , H. T. Jonkman , B. J. van Wees

In graphene, out-of-plane (flexural) vibrations and static ripples imposed by the substrate relax the electron spin, intrinsically protected by mirror symmetry. We calculate the relaxation times in different scenarios, accounting for all…

Mesoscale and Nanoscale Physics · Physics 2017-05-08 I. M. Vicent , H. Ochoa , F. Guinea

We investigate the conduction-band structure and electron mobility in rocksalt ScN based on density functional theory. The first-principles band structure allows us to obtain band velocities and effective masses as a function of energy.…

Materials Science · Physics 2021-08-18 Sai Mu , Andrew J. E. Rowberg , Joshua Leveillee , Feliciano Giustino , Chris G. Van de Walle

We investigate spin transport in quasi 2DEG formed by III-V semiconductor heterojunctions using the Monte Carlo method. The results obtained with and without electron-electron scattering are compared and appreciable difference between the…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Akashdeep Kamra , Bahniman Ghosh

We numerically study spin transport and nonequilibrium spin-density profiles in a clean one-dimensional spin-chain with long-range interactions, decaying as a power-law,$r^{-\alpha}$ with distance. We find two distinct regimes of transport:…

Disordered Systems and Neural Networks · Physics 2019-03-27 Benedikt Kloss , Yevgeny Bar Lev

Spin precession experiments in lateral spin devices are a powerful tool for probing the spin transport properties of materials. These experiments can be quantitatively described using the Bloch diffusion equation, which offers a practical…

We present a unified theoretical framework for the study of spin dynamics and relativistic transport phenomena in disordered two-dimensional Dirac systems with pseudospin-spin coupling. The formalism is applied to the paradigmatic case of…

Mesoscale and Nanoscale Physics · Physics 2018-07-11 Manuel Offidani , Roberto Raimondi , Aires Ferreira

We set up a set of many-body kinetic Bloch equations with spacial inhomogeneity. We reexamine the widely adopted quasi-independent electron model (QIEM) and show the inadequacy of this model in studying the spin transport. We further point…

Condensed Matter · Physics 2007-05-23 M. Q. Weng , M. W. Wu
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