Anisotropy of Electronic Spin Texture in the High-Temperature Cuprate Superconductor Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$
Wenjing Liu1,2, Heming Zha1,2, Gen-Da Gu3, Xiaoping Shen4, Mao Ye1,2*, and Shan Qiao1,2,5*
1State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China 2Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China 3Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA 4State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China 5School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
Abstract：Seeking new order parameters and the related broken symmetry and studying their relationship with phase transition have been important topics in condensed matter physics. Here, by using spin- and angle-resolved photoemission spectroscopy, we confirm the helical spin texture caused by spin-layer locking in the nodal region in the cuprate superconductor Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ and discover the anisotropy of spin polarizations at nodes along $\varGamma$–$X$ and $\varGamma$–$Y$ directions. The breaking of $C_{4}$ rotational symmetry in electronic spin texture may give deeper insights into understanding the ground state of cuprate superconductors.
2023, Vol. 40 
