Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2011-08-25
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
Scientific paper
Quantum effects are expected to disappear in the short-wavelength, semiclassical limit. As a matter of fact, recent investigations of transport through quantum chaotic systems have demonstrated the exponential suppression of the weak localization corrections to the conductance and of the Fano factor for shot-noise when the Ehrenfest time exceeds the electronic dwell time. On the other hand, conductance fluctuations, an effect of quantum coherence, retain their universal value in the limit of the ratio of Ehrenfest time over dwell time to infinity, when the system is ideally coupled to external leads. Motivated by this intriguing result we investigate conductance fluctuations through quantum chaotic cavities coupled to external leads via (tunnel) barriers of arbitrary transparency. Using the trajectory-based semiclassical theory of transport, we find a linear Ehrenfest time-dependence of the conductance variance showing a nonmonotonous, sinusoidal behavior as a function of the transperancy. Most notably, we find an increase of the conductance fluctuations with the Ehrenfest time, above their universal value, for the transparency less than 0.5. These results, confirmed by numerical simulations, show that, contrarily to the common wisdom, effects of quantum coherence may increase in the semiclassical limit, under special circumstances.
Jacquod Philippe
Kuipers J. J.
Richter Klaus
Waltner Daniel
No associations
LandOfFree
Conductance fluctuations in chaotic systems with tunnel barriers does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Conductance fluctuations in chaotic systems with tunnel barriers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Conductance fluctuations in chaotic systems with tunnel barriers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-319211