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Shot noise in semiclassical chaotic cavities
1Département de Physique Théorique, Université de Genève, CH-1211 Genève 4, Switzerland and Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble, France.
Physical Review Letters
|June 29, 2006
Summary
This study develops a semiclassical theory for shot noise in chaotic cavities. The Fano factor is exponentially suppressed as Ehrenfest time increases, preserving unitarity and offering insights into semiclassical validity.
Area of Science:
- Mesoscopic physics
- Quantum chaos
- Condensed matter theory
Background:
- Shot noise in chaotic cavities is crucial for understanding quantum transport.
- Existing theories often rely on random matrix theory (RMT) in the universal regime.
- The role of Ehrenfest time in semiclassical descriptions of shot noise requires further clarification.
Purpose of the Study:
- To construct a trajectory-based semiclassical theory for shot noise in clean chaotic cavities.
- To investigate the behavior of the Fano factor as a function of Ehrenfest time.
- To demonstrate the preservation of unitarity in the scattering matrix within the semiclassical framework.
Main Methods:
- Development of a novel trajectory-based semiclassical approach.
- Analysis of shot noise properties in the universal regime of vanishing Ehrenfest time.
- Examination of the Fano factor's dependence on increasing Ehrenfest time.
- Verification of scattering matrix unitarity for finite Ehrenfest times.
Main Results:
- Reproduced RMT results in the universal regime (zero Ehrenfest time).
- Showed exponential suppression of the Fano factor with increasing Ehrenfest time.
- Demonstrated that the developed theory maintains unitarity of the scattering matrix even for finite Ehrenfest times.
Conclusions:
- The trajectory-based semiclassical theory provides a consistent description of shot noise in chaotic cavities.
- The Ehrenfest time plays a critical role in suppressing shot noise beyond the universal regime.
- The theory clarifies subtleties in previous semiclassical treatments and establishes its range of validity.
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