Charge-relaxation and dwell time in the fluctuating admittance of a chaotic cavity
Instituut-Lorentz, University of Leiden - P.O. Box 9506, 2300 RA Leiden, The Netherlands
2 Département de Physique Théorique, Université de Genève - CH-1211 Genève 4, Switzerland
Accepted: 28 January 1997
We consider the admittance of a chaotic quantum dot, capacitively coupled to a gate and connected to two electron reservoirs by multichannel ballistic point contacts. For a dot in the regime of weak localization and universal conductance fluctuations, we calculate the average and variance of the admittance using random-matrix theory. We find that the admittance is governed by two time scales: the classical admittance depends on the RC time τ of the quantum dot, but the relevant time scale for the weak-localization correction and the admittance fluctuations is the dwell time. An extension of the circular ensemble is used for a statistical description of the energy dependence of the scattering matrix.
PACS: 05.45.+b – Theory and models of chaotic systems / 72.10.Bg – General formulation of transport theory / 72.30.+q – High-frequency effects; plasma effects
© EDP Sciences, 1997