Spin-Based Magnetofingerprints and Dephasing in Strongly Disordered Au-Nanobridges

TL;DR

This paper explores spin-based magnetofingerprints caused by the Zeeman effect in disordered gold nanobridges, revealing breakdown of Fermi liquid behavior at certain length scales through a new model and experimental data.

Contribution

It introduces a model based on Landauer-Buttiker formalism to describe unconventional magnetofingerprints caused by Zeeman effect in disordered nanostructures.

Findings

Magnetofingerprints are caused by Zeeman effect, not Aharonov-Bohm effect.

Dephasing time relates to correlation magnetic field and energy.

Fermi liquid description breaks down at length scales near localization length.

Abstract

We investigate quantum interference effects with magnetic field (magnetofingerprints) in strongly disordered Au-nanobridges. The magnetofingerprints are unconventional because they are caused by the Zeeman effect, not by the Aharonov-Bohm effect. These spin-based magnetofingerprints are equivalent to the Ericson's fluctuations (the fluctuations in electron transmission probability with electron energy). We present a model based on the Landauer-Buttiker formalism that describes the data. We show that the dephasing time $\tau_\phi (E,T)$ of electrons at temperature $T$ and energy $E$ above the Fermi level can be obtained from the correlation magnetic field. In samples with localization length comparable to sample size, $h/\tau_\phi (E,T) \approx E$, for $E\gg k_B T$, which shows that the Fermi liquid description of electron transport breaks down at length scale comparable to the localization length.