Exponential sensitivity to dephasing of electrical conduction through a quantum dot

Abstract

According to random-matrix theory, interference effects in the conductance of a ballistic chaotic quantum dot should vanish $\propto ({\tau }_{\varphi }/{\tau }_D{)}^p$ when the dephasing time ${\tau }_{\varphi }$ 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 $\propto \exp (-{\tau }_E/{\tau }_{\varphi })$ when ${\tau }_{\varphi }$ 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.

4 pages, 4 figures

References in corpus (3)

• Effects of dephasing on shot-noise in an electronic Mach-Zehnder interferometer
• Quantum-to-classical crossover of mesoscopic conductance fluctuations
• Noise and Measurement Efficiency of a Partially Coherent Mesoscopic Detector

Cited by in corpus (3)

• Ehrenfest-time dependence of weak localization in open quantum dots
• Classical limit of transport in quantum kicked maps
• Quantum-to-classical crossover for Andreev billiards in a magnetic field