Effect of a Voltage Probe on the Phase-Coherent Conductance of a Ballistic Chaotic Cavity

TL;DR

This paper uses random-matrix theory to analyze how an invasive voltage probe affects phase-coherent conductance in a ballistic chaotic cavity, revealing a transition from a power-law to a Gaussian conductance distribution.

Contribution

It provides the first detailed calculation of the conductance distribution in a chaotic cavity with a voltage probe, highlighting the crossover due to phase decoherence.

Findings

Loss of phase coherence causes a shift from power-law to Gaussian conductance distribution.

The conductance distribution depends on the presence or absence of time-reversal symmetry.

The study quantifies how a voltage probe influences phase-coherent transport in mesoscopic systems.

Abstract

The effect of an invasive voltage probe on the phase-coherent conduction through a ballistic chaotic cavity is investigated by random-matrix theory. The entire distribution P(G) of the conductance G is computed for the case that the cavity is coupled to source and drain by two point contacts with a quantized conductance of 2 e^2/h, both in the presence (beta = 1) and absence (beta = 2) of time-reversal symmetry. The loss of phase-coherence induced by the voltage probe causes a crossover from P(G) ~ G^(-1 + beta/2) to a Gaussian centered at G = e^2/h with a beta-dependent width. ***Submitted to Physical Review B.***