• Rapid Communication
  • Open Access

Fundamental limits to helical edge conductivity due to spin-phonon scattering

Solofo Groenendijk, Giacomo Dolcetto, and Thomas L. Schmidt
Phys. Rev. B 97, 241406(R) – Published 13 June 2018

Abstract

We study the effect of electron-phonon interactions on the electrical conductance of a helical edge state of a two-dimensional topological insulator. We show that the edge deformation caused by bulk acoustic phonons modifies the spin texture of the edge state, and that the resulting spin-phonon coupling leads to inelastic backscattering which makes the transport diffusive. Using a semiclassical Boltzmann equation we compute the electrical conductivity and show that it exhibits a metallic Bloch-Grüneisen law. At temperatures on the order of the Debye temperature of the host material, spin-phonon scattering thus drastically lowers the conductivity of the edge state. Transport remains ballistic only for short enough edges, and in this case the correction to the quantized conductance vanishes as δGT5 at low temperatures. Relying only on parallel transport of the helical spin texture along the deformed edge, the coupling strength is determined by the host material's density and sound velocity. Our results impose fundamental limits for the finite-temperature conductivity of a helical edge channel.

  • Figure
  • Figure
  • Figure
  • Received 28 November 2017

DOI:https://doi.org/10.1103/PhysRevB.97.241406

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Solofo Groenendijk, Giacomo Dolcetto, and Thomas L. Schmidt

  • Physics and Materials Science Research Unit, University of Luxembourg, L-1511 Luxembourg

Article Text

Click to Expand

References

Click to Expand
Issue

Vol. 97, Iss. 24 — 15 June 2018

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

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

×

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×