title: High-Tc superconductivity in ultrathin Bi2Sr2CaCu2O(8+x) down to half-unit-cell thickness by protection with graphene.
abstract: High-Tc superconductors confined to two dimension exhibit novel physical phenomena, such as superconductor-insulator transition. In the Bi2Sr2CaCu2O(8+x) (Bi2212) model system, despite extensive studies, the intrinsic superconducting properties at the thinness limit have been difficult to determine. Here, we report a method to fabricate high quality single-crystal Bi2212 films down to half-unit-cell thickness in the form of graphene/Bi2212 van der Waals heterostructure, in which sharp superconducting transitions are observed. The heterostructure also exhibits a nonlinear current-voltage characteristic due to the Dirac nature of the graphene band structure. More interestingly, although the critical temperature remains essentially the same with reduced thickness of Bi2212, the slope of the normal state T-linear resistivity varies by a factor of 4-5, and the sheet resistance increases by three orders of magnitude, indicating a surprising decoupling of the normal state resistance and superconductivity. The developed technique is versatile, applicable to investigate other two-dimensional (2D) superconducting materials.
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Da
authors.initials: D
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Lixing
authors.initials: L
authors.lastname: You
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Ang
authors.initials: A
authors.lastname: Li
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Haomin
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Mu
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Zhiying
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Haoran
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Yu
authors.affiliation: Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.affiliation: 1] State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China [2] School of Physics and Electronics, Central South University, Changsha 410083, China.
authors.forename: Qiujuan
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Max-Planck-Institute für Festkörperforschung, 70569 Stuttgart, Germany.
authors.forename: Chengtian
authors.initials: C
authors.lastname: Lin
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xiao
authors.affiliation: 1] State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China [2] School of Physical Science and Technology, ShanghaiTech University, 319 Yueyang Road, Shanghai 200031, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Xie
authors.affiliation: 1] State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China [2] School of Physical Science and Technology, ShanghaiTech University, 319 Yueyang Road, Shanghai 200031, China.
authors.forename: Mianheng
authors.initials: M
authors.lastname: Jiang