Transport spectroscopy in a time-modulated open quantum dot

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.Comment: 8 pages, 5 figure