Localisation determines the optimal noise rate for quantum transport

Alexandre Coates, Brendon W. Lovett, Erik M. Gauger

Research output: Contribution to journalArticlepeer-review

Abstract

Environmental noise plays a key role in determining the efficiency of transport in quantum systems. However, disorder and localisation alter the impact of such noise on energy transport. To provide a deeper understanding of this relationship we perform a systematic study of the connection between eigenstate localisation and the optimal dephasing rate in 1D chains. The effects of energy gradients and disorder on chains of various lengths are evaluated and we demonstrate how optimal transport efficiency is determined by both size-independent, as well as size-dependent factors. By discussing how size-dependent influences emerge from finite size effects we establish when these effects are suppressed, and show that a simple power law captures the interplay between size-dependent and size-independent responses. Moving beyond phenomenological pure dephasing, we implement a finite temperature Bloch-Redfield model that captures detailed balance. We show that the relationship between localisation and optimal environmental coupling strength continues to apply at intermediate and high temperature but breaks down in the low temperature limit.
Original languageEnglish
Article number123014
JournalNew Journal of Physics
Volume23
Early online date18 Nov 2021
DOIs
Publication statusPublished - Dec 2021

Keywords

  • quant-ph
  • cond-mat.other
  • physics.chem-ph

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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