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DY: Fachverband Dynamik und Statistische Physik

DY 21: Quantum chaos II

DY 21.4: Talk

Thursday, March 26, 2009, 11:00–11:15, ZEU 255

A semiclassical approach to the ac conductance of quantum chaotic cavities — •Cyril Petitjean, Daniel Waltner, Jack Kuipers, Inanc Adagideli, and Klaus Richter — Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg, Germany

Due to progress in the control and manipulation of mesoscopic structures driven by high frequency periodic voltages, the ac regime has recently been experimentally investigated [1] and consequently theoretical interest in it has been renewed. We consider a quantum chaotic cavity that is coupled via (tunnel) barriers and gates to a macroscopic circuit which contains ac-sources. For the transparent barrier, our semiclassical techniques permit us to include the Ehrenfest time in the weak-localization correction to the screened conductance, previously obtained by random matrix theory [2]. Then by extending recent semiclassical theory in presence of tunnel barriers [3] to the ac-transport, we investigate the effect of dephasing on the relaxation resistance of a chaotic capacitor in the linear low frequency regime. This last investigation is in principle relevant to the recent measurements of the admittance at zero magnetic flux of a mesoscopic capacitor [1,4].

[1] J. Gabelli et al., Science 313, 499 (2006).

[2] P.W. Brouwer and M. Büttiker, Europhys. Lett. 37, 441 (1997).

[3] R.S. Whitney, Phys. Rev. B, 75, 235404 (2007).

[4] S. Nigg and M. Büttiker, Phys. Rev. B 77, 085312 (2008).