# Macroscopic-ranged proximity effect in graphite

## TL;DR

This paper reports the observation of an unexpectedly large proximity effect in graphite, suggesting pre-existing superconducting correlations possibly linked to intrinsic superconductivity in twisted graphene layers.

## Contribution

It provides experimental evidence of a macroscopic proximity effect in graphite, indicating inherent superconducting correlations in the material.

## Key findings

- Large proximity effect observed over millimeters
- Supports presence of pre-existing superconducting correlations
- Consistent with intrinsic superconductivity in twisted graphene layers

## Abstract

We report the observation of proximity effect in measurements performed on highly oriented pyrolitic graphite (HOPG) samples when electrical current is injected through the superconducting electrodes placed on the sample surface few millimeters apart from each other. Such anomalously large effect is surprising, as proximity-induced superconducting features in normal conductors hardly surpass few micrometers. The obtained results can be consistently understood, however, considering pre-existing superconducting correlations in graphite, supported by recent observations of the intrinsic global superconductivity in twisted bi- and multi-layer graphenes.