Transport spectroscopy in a time-modulated open quantum dot

TL;DR

This paper explores how high-frequency time modulation affects quantum transport in open quantum dots, revealing resonant scattering phenomena and their signatures in conductance.

Contribution

It introduces a time-dependent mode-matching method to analyze resonant scatterings and dwell times in a modulated quantum dot system, highlighting new scattering processes.

Findings

Identification of three types of resonant scatterings under high-frequency modulation

Observation of Fano and dip structures in conductance signatures

Estimation of electron round-trip scatterings at resonant conditions

Abstract

We have investigated the time-modulated coherent quantum transport phenomena in a ballistic open quantum dot. The conductance $G$ and the electron dwell time in the dots are calculated by a time-dependent mode-matching method. Under high-frequency modulation, the traversing electrons are found to exhibit three types of resonant scatterings. They are intersideband scatterings: into quasibound states in the dots, into true bound states in the dots, and into quasibound states just beneath the subband threshold in the leads. Dip structures or fano structures in $G$ are their signatures. Our results show structures due to 2$\hbar\omega$ intersideband processes. At the above scattering resonances, we have estimated, according to our dwell time calculation, the number of round-trip scatterings that the traversing electrons undertake between the two dot openings.