Unidirectional valley-contrasting photocurrent in strained transition metal dichalcogenide monolayers

Reza Asgari and Dimitrie Culcer
Phys. Rev. B 105, 195418 – Published 16 May 2022

Abstract

We examine the full static nonlinear optical response of uniaxially strained transition metal dichalcogenide monolayers doped with a finite carrier density in the conduction band, in the presence of disorder. We find that the customary shift current is suppressed, yet we identify a strong, valley-dependent nonreciprocal response, which we term a unidirectional valley-contrasting photocurrent (UVCP). This DC current originates from the combined effect of strain and Kramers symmetry breaking by trigonal warping, while the contributions due to individual valleys can be separated by introducing an energy offset between them by means of a magnetization. This latter fact enables one to monitor intervalley transitions. The UVCP is proportional to the mobility and is enhanced by the excitonic Coulomb interaction and intervalley scattering, as well as by a top gate bias. We discuss detection strategies in state-of-the-art experiments.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
2 More
  • Received 14 December 2021
  • Revised 27 April 2022
  • Accepted 2 May 2022

DOI:https://doi.org/10.1103/PhysRevB.105.195418

©2022 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Reza Asgari1,2,3 and Dimitrie Culcer1,2

  • 1School of Physics, University of New South Wales, Kensington, New South Wales 2052, Australia
  • 2ARC Centre of Excellence in Future Low-Energy Electronics Technologies, UNSW Node, Sydney 2052, Australia
  • 3School of Physics, Institute for Research in Fundamental Sciences, IPM, Tehran 19395-5531, Iran

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 105, Iss. 19 — 15 May 2022

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×