Dresden 2003 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 20: Postersitzung IV (Mesoskopische Systeme, Supraleitung: Massivmaterialien, Bandleiter, Pinning, Vortexdynamik, Transporteigenschaften, Korngrenzen)

TT 20.1: Poster

Donnerstag, 27. März 2003, 14:30–19:00, P2c, P2d

Stochastic Path Integral Formulation of Full Counting Statistics — •Sebastian Pilgram, Andrew N. Jordan, Eugene V. Sukhorukov, and Markus Buttiker — Departement de Physique Theorique, Universite de Geneve, CH-1211 Geneve 4, Switzerland

We derive a stochastic path integral representation of counting statistics in semi-classical systems. Our approach is based on a separation of time scales: fast microscopic fluctuations (like current fluctuations in quantum point contacts) cause slow variations of conserved quantities (like the charge inside semi-classical conductors). We use this separation of time scales to represent the propagator for the charge distribution by a path integral which can be evaluated in saddle point approximation; fluctuations around the saddle point are suppressed in the semi-classical limit.

The formalism is introduced on the simple case of a single chaotic cavity with two quantum point contacts, and then further generalized to find the propagator for charge distributions with an arbitrary number of counting fields and generalized charges. As a new and experimentally interesting application we present the full counting statistics of a chaotic cavity in the hot-electron regime and give analytical expressions for current cumulants at arbitrary voltage and temperature.