Related papers: Electrically Controlled Pumping of Spin Currents i…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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…
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.…
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…