Tunable valley filtering in dynamically strained αT3 lattices

Alexander Filusch and Holger Fehske
Phys. Rev. B 106, 245106 – Published 5 December 2022

Abstract

Mechanical deformations in αT3 lattices induce local pseudomagnetic fields of opposite directionality for different valleys. When this strain is equipped with a dynamical drive, it generates a complementary valley-asymmetric pseudoelectric field, which is expected to accelerate electrons. We propose that by combining these effects by a time-dependent nonuniform strain, tunable valley filtering devices can be engineered that extend beyond the static capabilities. We demonstrate this by implementing an oscillating Gaussian bump centered in a four-terminal Hall bar αT3 setup and calculating the induced pseudoelectromagnetic fields analytically. Within a recursive Floquet Green-function scheme, we determine the time-averaged transmission and valley polarization, as well as the spatial distributions of the local density of states and current density. As a result of the periodic drive, we detect novel energy regimes with a highly valley-polarized transmission, depending on α. Analyzing the spatial profiles of the time-averaged local density of states and current density we can relate these regimes to the pseudoelectromagnetic fields in the setup. By means of the driving frequency, we can manipulate the valley-polarized states, which might be advantageous for future device applications.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 19 June 2022
  • Revised 28 October 2022
  • Accepted 28 November 2022

DOI:https://doi.org/10.1103/PhysRevB.106.245106

©2022 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Alexander Filusch1 and Holger Fehske1,2,*

  • 1Institute of Physics, University Greifswald, 17487 Greifswald, Germany
  • 2Erlangen National High Performance Computing Center, 91058 Erlangen, Germany

  • *fehske@physik.uni-greifswald.de

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 106, Iss. 24 — 15 December 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
×