Gate-controlled spin extraction from topological insulator surfaces

Ali Asgharpour, Cosimo Gorini, Sven Essert, Klaus Richter, İnanç Adagideli*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Spin-momentum locking, a key property of the surface states of three-dimensional topological insulators (3DTIs), provides a new avenue for spintronics applications. One consequence of spin-momentum locking is the induction of surface spin accumulations due to applied electric fields. In this paper, we investigate the extraction of such electrically induced spins from their host TI material into adjoining conventional, hence topologically trivial, materials that are commonly used in electronics devices. We focus on effective Hamiltonians for bismuth-based 3DTI materials in the Bi2Se3 family, and numerically explore the geometries for extracting current-induced spins from a TI surface. In particular, we consider a device geometry in which a side pocket is attached to various faces of a 3DTI quantum wire and show that it is possible to create current-induced spin accumulations in these topologically trivial side pockets. We further study how such spin extraction depends on geometry and material parameters, and find that electron-hole degrees of freedom can be utilized to control the polarization of the extracted spins by an applied gate voltage.

Original languageEnglish
Article number035401
JournalPhysical Review B
Volume102
Issue number3
DOIs
Publication statusPublished - 15 Jul 2020

Fingerprint

Dive into the research topics of 'Gate-controlled spin extraction from topological insulator surfaces'. Together they form a unique fingerprint.

Cite this