Spin-charge coupled transport in van der Waals systems with random tunneling

We study the electron and spin transport in a van der Waals system formed by one layer with strong spin-orbit coupling and a second layer without spin-orbit coupling, in the regime when the interlayer tunneling is random. We find that in the layer without intrinsic spin-orbit coupling, spin-charge c...

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Main Authors: M. Rodriguez-Vega, G. Schwiete, Enrico Rossi
Format: Article
Language:English
Published: American Physical Society 2019-11-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.1.033085
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author M. Rodriguez-Vega
G. Schwiete
Enrico Rossi
author_facet M. Rodriguez-Vega
G. Schwiete
Enrico Rossi
author_sort M. Rodriguez-Vega
collection DOAJ
description We study the electron and spin transport in a van der Waals system formed by one layer with strong spin-orbit coupling and a second layer without spin-orbit coupling, in the regime when the interlayer tunneling is random. We find that in the layer without intrinsic spin-orbit coupling, spin-charge coupled transport can be induced by two distinct mechanisms. First, the gapless diffusion modes of the two isolated layers hybridize in the presence of tunneling, which constitutes a source of spin-charge coupled transport in the second layer. Second, the random tunneling introduces spin-orbit coupling in the effective disorder-averaged single-particle Hamiltonian of the second layer. This results in nontrivial spin transport and, for sufficiently strong tunneling, in spin-charge coupling. As an example, we consider a van der Waals system formed by a two-dimensional electron gas (2DEG)—such as graphene—and the surface of a topological insulator (TI) and show that the proximity of the TI induces a coupling of the spin and charge transport in the 2DEG. In addition, we show that such coupling can be tuned by varying the doping of the TI's surface. We then obtain, for a simple geometry, the current-induced nonequilibrium spin accumulation (Edelstein effect) caused in the 2DEG by the coupling of charge and spin transport.
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spelling doaj.art-f14ee0769b354388976e502b5359205e2024-04-12T16:46:44ZengAmerican Physical SocietyPhysical Review Research2643-15642019-11-011303308510.1103/PhysRevResearch.1.033085Spin-charge coupled transport in van der Waals systems with random tunnelingM. Rodriguez-VegaG. SchwieteEnrico RossiWe study the electron and spin transport in a van der Waals system formed by one layer with strong spin-orbit coupling and a second layer without spin-orbit coupling, in the regime when the interlayer tunneling is random. We find that in the layer without intrinsic spin-orbit coupling, spin-charge coupled transport can be induced by two distinct mechanisms. First, the gapless diffusion modes of the two isolated layers hybridize in the presence of tunneling, which constitutes a source of spin-charge coupled transport in the second layer. Second, the random tunneling introduces spin-orbit coupling in the effective disorder-averaged single-particle Hamiltonian of the second layer. This results in nontrivial spin transport and, for sufficiently strong tunneling, in spin-charge coupling. As an example, we consider a van der Waals system formed by a two-dimensional electron gas (2DEG)—such as graphene—and the surface of a topological insulator (TI) and show that the proximity of the TI induces a coupling of the spin and charge transport in the 2DEG. In addition, we show that such coupling can be tuned by varying the doping of the TI's surface. We then obtain, for a simple geometry, the current-induced nonequilibrium spin accumulation (Edelstein effect) caused in the 2DEG by the coupling of charge and spin transport.http://doi.org/10.1103/PhysRevResearch.1.033085
spellingShingle M. Rodriguez-Vega
G. Schwiete
Enrico Rossi
Spin-charge coupled transport in van der Waals systems with random tunneling
Physical Review Research
title Spin-charge coupled transport in van der Waals systems with random tunneling
title_full Spin-charge coupled transport in van der Waals systems with random tunneling
title_fullStr Spin-charge coupled transport in van der Waals systems with random tunneling
title_full_unstemmed Spin-charge coupled transport in van der Waals systems with random tunneling
title_short Spin-charge coupled transport in van der Waals systems with random tunneling
title_sort spin charge coupled transport in van der waals systems with random tunneling
url http://doi.org/10.1103/PhysRevResearch.1.033085
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AT gschwiete spinchargecoupledtransportinvanderwaalssystemswithrandomtunneling
AT enricorossi spinchargecoupledtransportinvanderwaalssystemswithrandomtunneling