Localisation determines the optimal noise rate for quantum transport
MetadataShow full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
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.
Coates , A R , Lovett , B W & Gauger , E M 2021 , ' Localisation determines the optimal noise rate for quantum transport ' , New Journal of Physics , vol. 23 , no. 12 , 123014 . https://doi.org/10.1088/1367-2630/ac3b2c
New Journal of Physics
Copyright © 2021 The Author(s). Published by IOP Publishing Ltd on behalf of the Institute of Physics and Deutsche Physikalische Gesellschaft. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
DescriptionThis work was supported by EPSRC Grant No. EP/L015110/1.
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.