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

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.