FeSe超导薄膜的研究进展

Recent Progress in FeSe Superconducting Thin Film

FeSe及其相关化合物的高温超导性引起了凝聚态物理研究人员的广泛关注。在所有铁基超导体中,FeSe的成分和晶体结构最为简单,只存在铁基超导体最基本的结构单元FeSe层。FeSe超导体具有特殊的电子结构和物理特性,是铁基高温超导机制研究的理想平台。2012年,薛其坤组在SrTiO_3(STO)衬底表面采用分子束外延(MBE)法生长了单层FeSe薄膜,发现该体系的超导转变温度(TC)有接近80K的迹象,引起人们的广泛关注。先简要地介绍了FeSe晶体,FeSe/石墨烯薄膜的超导特性,再详细介绍了FeSe/SrTiO_3高温超导薄膜的输运性质、超导特性、电子结构以及可能影响单层FeSe/SrTiO_3薄膜高温超导的几个因素。

FeSe and its related compounds with high superconducting transition temperature（TC）have drawn great attentions in the field of condensed matter physics.FeSe has the simplest chemical and crystal structure which consists of only superconducting FeSe layers in iron-based superconductors.FeSe has the unique electronic structure and peculiar physical properties,which provides an ideal platform to study the mechanism of high temperature superconductivity.In 2012,Q.K.Xue et al grew single-layer FeSe thin films on SrTiO3 substrate by molecular beam epitaxy（MBE）,on which a superconducting gap as large as 20 meV was discovered.The gap corresponded to a superconducting transition temperature near 80 K,if we assumed the same relationship between the superconducting gap and TC with bulk FeSe.In this paper,we present a brief introduction of the bulk FeSe and the FeSe films on graphene,and make a detailed review on the electronic structure,superconductivity and the superconducting mechanism of the FeSe thin films grown on SrTiO3.