Regular Article

Supersolid phase of cold atoms^★

¹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P.R. China
² School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
³ Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Chinese Academy of Sciences, Xi’an 710600, P.R. China
⁴ School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
⁵ Fujian Provincial Key Laboratory for Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou 350117, P.R. China
⁶ Fujian Provincial Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen 361005, P.R. China
⁷ Department of Physics and Astronomy, Mississippi State University, Starkville, MS 39762, USA
⁸ Kavli Institute of Theoretical Physics, University of California, Santa Barbara, CA 93106, USA
⁹ Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, P.R. China

^a e-mail: wmliu@iphy.ac.cn

Received: 1 March 2020
Received in final form: 6 April 2020
Published online: 1 July 2020

Abstract

Supersolid phase is a phase of matter that is characterized by the combination of the off-diagonal long-range order of superfluid and the diagonal long-range order of solid. Cold atoms with spin–orbit-coupling, contact interaction and long-range interaction can provide systems for the research of supersolid phase. Under the effect of spin-dependent potential and spin–orbit-coupling, hard-core ultra-cold atoms with contact interaction can be shown to construct supersolid phase. The combination of soft-core long-range interaction and spin–orbit coupling can establish exotic supersolid phase with spontaneous breakdown of chiral symmetry. The optical Bragg scattering of cold atoms in optical lattices can be used to detect supersolid phase. The study of supersolid phase will be helpful to the researches of matter phases.