Doubling of the critical temperature of FeSe observed in point contacts

TL;DR

This paper reports a significant increase in the superconducting critical temperature of FeSe when formed into point contacts with copper, suggesting interfacial effects like doping or enhanced electron-phonon interactions as possible causes.

Contribution

It presents the first observation of more than doubling the Tc of FeSe in point-contact configurations and discusses potential interfacial mechanisms responsible.

Findings

Critical temperature exceeds 20 K in point contacts.

Interfacial doping and electron-phonon interaction likely cause Tc enhancement.

First experimental evidence of Tc doubling in FeSe point contacts.

Abstract

Rise in superconducting critical temperature Tc more than two times (exceeding 20 K) is discov- ered in point-contacts created between iron-chalcogenide FeSe single crystal and Cu. The possible reasons of such Tc increase in point-contacts are discussed. The most probable cause for this may be the interfacial carriers doping and/or interfacial enhanced electron-phonon interaction.