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

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Cited by in corpus (12)

• A semiclassical theory of the Ehrenfest-time dependence of quantum transport in ballistic quantum dots
• Ehrenfest-time dependence of weak localization in open quantum dots
• Towards a semiclassical justification of the `effective random matrix theory' for transport through ballistic chaotic quantum dots
• Controlled decoherence in a quantum Lévy kicked rotator
• Dephasing in quantum chaotic transport: a semiclassical approach
• Semiclassical theory of the Ehrenfest-time dependence of quantum transport
• Conductance fluctuations in chaotic systems with tunnel barriers
• Classical limit of transport in quantum kicked maps
• Interplay of Ehrenfest time and dephasing time in ballistic conductors
• Quantum-to-classical crossover for Andreev billiards in a magnetic field
• Semiclassical theory of a quantum pump
• Dephasing in the semiclassical limit is system-dependent