Doubling of the critical temperature of FeSe observed in point contacts

Abstract

A rise in the superconducting critical temperature Tc of more than two times (exceeding 20 K) is discovered in point contacts created between iron chalcogenide FeSe single crystals and Cu. The possible reasons for such a Tc increase in point contacts are discussed. The most likely cause for this may be the interfacial carrier doping and/or interfacial enhanced electron-phonon interaction. © 2016 American Physical Society.