Exciton spin Hall effect in arc-shaped strained WSe2

A. Shubnic, V. Shahnazaryan, I. A. Shelykh, H. Rostami

Research output: Contribution to journalArticlepeer-review

Abstract

Generating a pure spin current using electrons, which have degrees of freedom beyond spin, such as electric charge and valley index, presents challenges. In response, we propose a mechanism based on intervalley exciton dynamics in arc-shaped strained transition metal dichalcogenides (TMDs) to achieve the exciton spin Hall effect in an electrically insulating regime, without the need for an external electric field. The interplay between strain gradients and strain-induced pseudomagnetic fields results in a net Lorentz force on long-lived intervalley excitons in WSe2, carrying nonzero spin angular momentum. This process generates an exciton-mediated pure spin Hall current, resulting in opposite-sign spin accumulations and local magnetization on the two sides of the single-layer arc-shaped TMD. We demonstrate that the magnetic field induced by spin accumulation, at approximately ∼mT, can be detected using techniques such as superconducting quantum interference magnetometry or spatially resolved magneto-optical Faraday and Kerr rotations.

Original languageEnglish
Article numberL201409
JournalPhysical Review B
Volume109
Issue number20
DOIs
Publication statusPublished - 24 May 2024

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this