The Temperature dependence of the magneto-resistance peak in highly disordered superconductors

TL;DR

This study investigates how the magneto-resistance peak in highly disordered superconductors shifts with temperature, revealing a consistent activated resistance behavior linked to the superconductor-insulator transition.

Contribution

It provides new insights into the temperature evolution of the magneto-resistance peak and its relation to the quantum critical point in disordered superconductors.

Findings

Peak shifts to lower B as T decreases

Resistance follows an activated T dependence

Peak resistance is close to the quantum of resistance for Cooper pairs

Abstract

Highly disordered superconductors have a rich phase diagram. At a moderate magnetic field (B) the samples go through the superconductor-insulator quantum phase transition. In the insulating phase, the resistance increases sharply with B up to a magneto-resistance peak beyond which the resistance drops with B. In this manuscript we follow the temperature (T) evolution of this magneto-resistance peak. We show that as T is reduced, the peak appears at lower B's approaching the critical field of the superconductor-insulator transition. Due to experimental limitations we are unable to determine whether the T=0 limiting position of the peak matches that of the critical field or is at comparable but slightly higher B. We show that, although the peak appears at different B values, its resistance follows an activated T dependence over a large T range with a prefactor that is very similar to the quantum of resistance for cooper-pairs.