Ehrenfest-time dependence of quantum transport in ballistic quantum dots

Piet Brouwer

Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, USA

Shot noise, the weak localization correction to the conductance, and universal conductance fluctuations are manifestations of the wave nature of electrons. How these effects appear in a ballistic quantum dot is believed to depend on the ratio of the Ehrenfest time and the mean dwell time in the dot. The Ehrenfest time is the time necessary for a minimal wave packet to diverge a distance of the order of the size of the quantum dot. In my talk, I'll review the semiclassical theory of the Ehrenfest time dependence. Whereas shot noise and weak localization are suppressed if the Ehrenfest time is much larger than the dwell time, the conductance fluctuations are not. The latter is in agreement with numerical simulations of the quantum kicked rotator [Tworzydlo et al., PRB 69, 165318 (2004) and Jacquod and Sukhorukov, PRL 92, 116801 (2004)].