Exponential sensitivity to dephasing of electrical conduction through a quantum dot.

Tworzydlo, J. and Tajic, A. and Schomerus, H. and Brouwer, P. W. and Beenakker, C. W. J. (2004) Exponential sensitivity to dephasing of electrical conduction through a quantum dot. Physical review letters, 93. p. 186806.

[img]
Preview
PDF (000224799500062.pdf)
000224799500062.pdf

Download (110kB)

Abstract

According to random-matrix theory, interference effects in the conductance of a ballistic chaotic quantum dot should vanish propto(tau_phi/tau_D)^p when the dephasing time tau_phi becomes small compared to the mean dwell time tau_D. Aleiner and Larkin have predicted that the power law crosses over to an exponential suppression exp(�tau_E/tau_phi) when tau_phi drops below the Ehrenfest time tau_E. We report the first observation of this crossover in a computer simulation of universal conductance fluctuations. Their theory also predicts an exponential suppression propto exp(�tau_E/tau_D) in the absence of dephasing�which is not observed. We show that the effective random-matrix theory proposed previously for quantum dots without dephasing explains both observations.

Item Type:
Journal Article
Journal or Publication Title:
Physical review letters
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100
Subjects:
ID Code:
665
Deposited By:
Deposited On:
31 Oct 2007
Refereed?:
Yes
Published?:
Published
Last Modified:
02 Dec 2020 01:02