Quantum Point Contacts and Beyond: New Results on Mesoscopic Conductance and Fluctuations

TL;DR

This paper presents a microscopic kinetic theory for open quantum point contacts, emphasizing gauge invariance and sum rules, which impose strict constraints on transport and fluctuations, influencing observable properties of mesoscopic conductors.

Contribution

It introduces a new microscopic kinetic framework that incorporates gauge invariance and many-body sum rules for analyzing mesoscopic conductance and fluctuations in QPCs.

Findings

Constraints from gauge invariance shape conductance behavior.

Sum rules limit fluctuation magnitudes.

Phenomenological models are consistent with microscopic constraints.

Abstract

We summarize the main results of a microscopically based kinetic theory, applicable to open quantum point contacts (QPCs) driven up to high fields. The governing role of gauge invariance -- and the many-body sum rules for the electron gas -- lead to stringent constraints on both transport and fluctuations. These constraints exert a dominant influence on the observable properties of QPCs and similar open mesoscopic conductors. We illustrate this in the context of certain predictions within purely phenomenological models of mesoscopic transport.