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Finite frequency quantum noise in an interacting mesoscopic conductor
1Laboratoire de Physique et Modélisation des Milieux Condensés, CNRS & Université Joseph Fourier, Boîte Postale 166, 38042 Grenoble-cedex 9, France.
Physical Review Letters
|February 21, 2006
Summary
We calculated current noise in interacting chaotic cavities, revealing unique behaviors at specific frequencies related to charge relaxation time. This study highlights two key time scales: cavity dwell time and gate RC time.
Area of Science:
- Quantum transport phenomena
- Mesoscopic physics
- Electron-electron interactions
Background:
- Understanding current noise in quantum systems is crucial for developing advanced electronic devices.
- Electron interactions and cavity properties significantly influence quantum transport dynamics.
- Chaotic cavities with external gates present complex systems for theoretical investigation.
Purpose of the Study:
- To perform a quantum calculation of frequency-dependent current noise in an interacting chaotic cavity.
- To investigate the role of long-range Coulomb forces and gate capacitance on noise characteristics.
- To identify and analyze the distinct time scales governing the system's behavior.
Main Methods:
- Utilizing scattering theory for quantum calculations.
- Incorporating electron-electron interactions via Coulomb forces.
- Analyzing noise spectra across relevant frequency ranges.
Main Results:
- Explicit results demonstrating the interplay of two time scales: cavity dwell time (τD) and gate RC time (τC).
- Identification of noise peculiarities at frequencies related to the inverse charge relaxation time (τ−1).
- The derived charge relaxation time is a sum of the inverse dwell time and inverse RC time: τ−1 = τD−1 + τC−1.
Conclusions:
- The frequency-dependent noise in interacting chaotic cavities is characterized by two fundamental time scales.
- Coulomb interactions and gate coupling introduce unique features in the current noise spectrum.
- The findings provide insights into quantum transport in mesoscopic systems with electron interactions.
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