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Related papers: Electrically Controlled Pumping of Spin Currents i…

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We propose a one-dimensional electron model with parameters modulated adiabatically in closed cycles, which can continuously pump spin to leads. By defining the spin-polarized Wannier functions, we show that the spin pump is protected by…

Mesoscale and Nanoscale Physics · Physics 2016-01-27 C. Q. Zhou , Y. F. Zhang , L. Sheng , R. Shen , D. N. Sheng , D. Y. Xing

Topological pumping of ultracold atomic gases has recently been demonstrated in two experiments (Nat. Phys. 12, 296; 12, 350 (2016)). Here we study the topological pumping of a single magnon in a dynamically controlled spin-dependent…

Quantum Gases · Physics 2019-01-18 Feng Mei , Gang Chen , Liantuan Xiao , Suotang Jia

Thouless pumping is a mechanism to perform topologically protected transport of particles by adiabatically modulating the Hamiltonian. The transported current is a topological invariant that is intimately related to the integer quantum Hall…

Quantum Physics · Physics 2023-01-06 V. M. Bastidas

Spin currents are key to spin torque devices, but determining the proper spin current is non-trivial. Here we derive a general quantum-mechanical formula for the intrinsic proper spin current showing that it is topological and can be finite…

Mesoscale and Nanoscale Physics · Physics 2024-02-13 Hong Liu , James H. Cullen , Dimitrie Culcer

To date, spin generation in three-dimensional topological insulators is primarily modeled as a single-surface phenomenon, attributed to the momentum-spin locking on each individual surface. In this article we propose a mechanism of spin…

Materials Science · Physics 2016-01-08 Xingyue Peng , Yiming Yang , Rajiv R. P. Singh , Sergey Y. Savrasov , Dong Yu

We microscopically analyze thermal spin pumping mediated by magnons, at the interface between a ferromagnetic insulator and a non-magnetic metal, in the semiclassical regime. The generation of a spin current is discussed by calculating the…

Mesoscale and Nanoscale Physics · Physics 2012-05-24 Kouki Nakata

Topological spintronics aims to exploit the spin-momentum locking in the helical surface states of topological insulators for spin-orbit torque devices. We address a fundamental question that still remains unresolved in this context: does…

We propose a device acting as a spin valve which is based on a double quantum dot structure with parallel topology. Using the exact analytical solution for the noninteracting case we argue that, at a certain constellation of system…

Mesoscale and Nanoscale Physics · Physics 2010-03-18 J. P. Dahlhaus , S. Maier , A. Komnik

We show that the interplay between chiral tunneling and spin-momentum locking of helical surface states leads to spin amplification and filtering in a 3D Topological Insulator (TI). Chiral tunneling across a TI pn junction allows normally…

Mesoscale and Nanoscale Physics · Physics 2015-03-23 K. M. Masum Habib , Redwan N. Sajjad , Avik W. Ghosh

The adiabatic topological pumping is proposed by periodically modulating a semiconductor nanowire double-quantum-dot chain. We demonstrate that the quantized charge transport can be achieved by a nontrivial modulation of the quantum-dot…

Mesoscale and Nanoscale Physics · Physics 2021-11-23 Zhi-Hai Liu , H. Q. Xu

Topological insulators (TIs) are a new quantum state of matter discovered recently, which are characterized by unconventional bulk topological invariants. Proposals for practical applications of the TIs are mostly based upon their metallic…

Mesoscale and Nanoscale Physics · Physics 2016-01-15 M. N. Chen , L. Sheng , R. Shen , D. N. Sheng , D. Y. Xing

We study charge and spin pumping in an interacting one-dimensional wire. We show that a spatially periodic potential modulated in space and time acts as a quantum pump inducing a dc-current component at zero bias. The current generated by…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 R. Citro , N. Andrei , Q. Niu

We show that a magnetic line defect on the surface of a topological insulator generically supports two distinct branches of spin-polarized and current carrying one-dimensional bound states. We identify the components of magnetic scattering…

Mesoscale and Nanoscale Physics · Physics 2024-01-17 Eklavya Thareja , Ilya Vekhter

Several recent experiments on three-dimensional topological insulators claim to observe a large charge current-induced non-equilibrium ensemble spin polarization of electrons in the helical surface state. We present a comprehensive…

Materials Science · Physics 2016-06-29 Pengke Li , Ian Appelbaum

We present a prescription for generating pure spin current or spin selective current, based on adiabatic quantum pumping in a tight-binding model of a one dimensional conductor. A formula for the instantaneous pumped current is derived…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Sungjun Kim , Kunal K. Das , Ari Mizel

The control and generation of spin-polarized currents (SPCs) without magnetic materials and external magnetic field is a big challenge in spintronics and normally requires spin-flip mechanism. In this work, we propose a novel method to…

Mesoscale and Nanoscale Physics · Physics 2017-03-29 L. L. Tao , K. T. Cheung , L. Zhang , J. Wang

Nanoscale single-electron pumps can be used to generate accurate currents, and can potentially serve to realize a new standard of electrical current based on elementary charge. Here, we use a silicon-based quantum dot with tunable tunnel…

Mesoscale and Nanoscale Physics · Physics 2014-06-26 A. Rossi , T. Tanttu , K. Y. Tan , I. Iisakka , R. Zhao , K. W. Chan , G. C. Tettamanzi , S. Rogge , A. S. Dzurak , M. Möttönen

We predict the appearance of a persistent spin current in a two-dimensional electron gas formed at the interface of multiferroic oxides with a transverse helical magnetic order. No charge current is generated. This is the result of an…

Mesoscale and Nanoscale Physics · Physics 2009-07-20 Chenglong Jia , Jamal Berakdar

Particle-particle interaction provides a new degree of freedom to induce novel topological phenomena. Here, we propose to use spatiotemporal modulation of interaction to realize topological pumping without single-particle counterpart.…

Mesoscale and Nanoscale Physics · Physics 2024-10-28 Boning Huang , Yongguan Ke , Wenjie Liu , Chaohong Lee

We analyze theoretically the bound state spectrum of an Aharonov Bohm (AB) ring in a two-dimensional topological insulator using the four-band model of HgTe-quantum wells as a concrete example. We calculate analytically the circular helical…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 Paolo Michetti , Patrik Recher