Evidence of Josephson-coupled superconducting regions at the interfaces of Highly Oriented Pyrolytic Graphite

TL;DR

This study provides evidence that internal interfaces in highly oriented pyrolytic graphite host Josephson-coupled superconducting regions with critical temperatures exceeding 100 K, as demonstrated by transport measurements.

Contribution

It reveals the presence of high-temperature superconducting regions at internal interfaces of HOPG, a novel finding in graphite materials.

Findings

Superconducting regions embedded in HOPG interfaces reach zero resistance at low temperatures.

Transport measurements indicate Josephson coupling at internal interfaces.

Critical temperatures of these regions exceed 100 K.

Abstract

Transport properties of a few hundreds of nanometers thick (in the graphene plane direction) lamellae of highly oriented pyrolytic graphite (HOPG) have been investigated. Current-Voltage characteristics as well as the temperature dependence of the voltage at different fixed input currents provide evidence for Josephson-coupled superconducting regions embedded in the internal two-dimensional interfaces, reaching zero resistance at low enough temperatures. The overall behavior indicates the existence of superconducting regions with critical temperatures above 100 K at the internal interfaces of oriented pyrolytic graphite.