Quantum shot-noise at local tunneling contacts on mesoscopic multiprobe conductors

TL;DR

This paper proposes experiments to measure low-frequency shot-noise spectra at local tunneling contacts on mesoscopic conductors, revealing information about local densities of states and electronic wave function correlations.

Contribution

It introduces a novel experimental approach to probe local and non-local electronic correlations in mesoscopic systems using shot-noise measurements.

Findings

Current fluctuation spectrum relates to local partial densities of states.

Cross-correlation spectrum reveals non-diagonal density of states elements.

Results demonstrated for a clean wire with a barrier and diffusive conductors.

Abstract

New experiments that measure the low-frequency shot-noise spectrum at local tunneling contacts on mesoscopic structures are proposed. The current fluctuation spectrum at a single tunneling tip is determined by local partial densities of states. The current-correlation spectrum between two tunneling tips is sensitive to non-diagonal density of states elements which are expressed in terms of products of scattering states of the conductor. Thus such an experiment permits to investigate correlations of electronic wave functions. We present specific results for a clean wire with a single barrier and for metallic diffusive conductors.