Observation of a superconducting glass state in granular superconducting diamond

TL;DR

This paper reports the discovery of a superconducting glass state in nanocrystalline boron-doped diamond films, characterized through resistance and magnetic relaxation measurements, advancing understanding of their phase diagram.

Contribution

It provides detailed phase boundary mapping in the H-T plane using fluctuation conductivity theory, revealing a glass state in superconducting diamond.

Findings

Evidence of a glass state in the phase diagram

Precise determination of the resistive boundary

Superconductivity behavior characterized by fluctuation conductivity

Abstract

The magnetic field dependence of the superconductivity in nanocrystalline boron doped diamond thin films is reported. Evidence of a glass state in the phase diagram is presented, as demonstrated by electrical resistance and magnetic relaxation measurements. The position of the phase boundary in the H-T plane is determined from resistance data by detailed fitting to zero-dimensional fluctuation conductivity theory. This allows determination of the boundary between resistive and non-resistive behavior to be made with greater precision than the standard ad hoc onset/midpoint/offset criterion.