Observation of thermally activated glassiness and memory dip in a-NbSi insulating thin films

Abstract

We present electrical conductance measurements on amorphous NbSi insulating thin films. These films display out-of equilibrium electronic features that are markedly different from what has been reported so far in disordered insulators. Like in the most studied systems (indium oxide and granular Al films), a slow relaxation of the conductance is observed after a quench to liquid helium temperature which gives rise to the growth of a memory dip in MOSFET devices. But unlike in these systems, this memory dip and the related conductance relaxations are still visible up to room temperature, with clear signatures of a temperature dependent dynamics.

References in corpus (6)

• Symmetrical field effect and slow electron relaxation in granular aluminium
• Relaxation dynamics in quantum electron-glasses
• A quench-cooling procedure compared with the gate-protocol for aging experiments in the Electron-Glass
• Effect of annealing on the superconducting properties of a-Nb(x)Si(1-x) thin films
• Intrinsic electron-glassiness in strongly-localized Be films
• Slow Conductance Relaxation in Insulating Granular Al: Evidence for Screening Effects

Cited by in corpus (3)

• Evidence for thermal activation in the glassy dynamics of insulating granular aluminum conductance
• Electron glass signatures up to room temperature in disordered insulators
• Anomalous thermal activation of the electron glass dynamics in a-InOx and granular aluminum