Nonequilibrium phase transition in transport through a driven quantum point contact

Oleksandr Gamayun, Artur Slobodeniuk, Jean Sébastien Caux, Oleg Lychkovskiy

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

We study the transport of noninteracting fermions through a periodically driven quantum point contact (QPC) connecting two tight-binding chains. Initially, each chain is prepared in its own equilibrium state, generally with a bias in chemical potentials and temperatures. We examine the heating rate (or, alternatively, energy increase per cycle) in the nonequilibrium time-periodic steady state established after initial transient dynamics. We find that the heating rate vanishes identically when the driving frequency exceeds the bandwidth of the chain. We first establish this fact for a particular type of QPCs where the heating rate can be calculated analytically. Then we verify numerically that this nonequilibrium phase transition is present for a generic QPC. Finally, we derive this effect perturbatively in leading order for cases when the QPC Hamiltonian can be considered a small perturbation. Strikingly, we discover that for certain QPCs the current averaged over the driving cycle also vanishes above the critical frequency, despite a persistent bias. This shows that a driven QPC can act as a frequency-controlled quantum switch.

Original languageEnglish
Article numberL041405
JournalPhysical Review B
Volume103
Issue number4
DOIs
Publication statusPublished - 22 Jan 2021

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