Observation of nodal-line semimetal with ultracold fermions in an optical lattice

Song, Bo1; He, Chengdong1; Niu, Sen2,3; Zhang, Long2,3; Ren, Zejian1; Liu, Xiong-Jun2,3,4,5,6; Jo, Gyu-Boong1

2019-09

10.1038/s41567-019-0564-y

Nature Physics   影响因子和分区

1745-2473

1745-2481

The observation of topological phases beyond two dimensions, as widely reported in solid-state systems(1,2), has been an open challenge for ultracold atoms. Although many theoretical schemes have been proposed, the experimental complexity in realizing and characterizing the three-dimensional (3D) band structure has acted as a barrier against experiments achieving this. Here, we realize a 3D spin-orbit coupled nodal-line semimetal in an optical Raman lattice filled with ultracold fermions, and observe the bulk line nodes in the band structure. The realized topological semimetal exhibits an emergent magnetic group symmetry. This allows detection of the nodal lines by effectively reconstructing the 3D topological band from a series of measurements of integrated spin textures, which precisely render spin textures on the parameter-tuned magnetic-group-symmetric planes. The detection technique can be applied generally to explore 3D topological states of similar symmetries. Furthermore, we observe the band inversion lines from topological quench dynamics, which are bulk counterparts of Fermi arc states and connect the Dirac points, reconfirming the realized topological band. Our results demonstrate an approach to effectively observe 3D band topology, and open the way to probe exotic topological physics for ultra-cold atoms in high dimensions.

SCI ; EI

英语

NI期刊

通讯

Strategic Priority Research Program of the Chinese Academy of Science[XDB28000000]

Physics

Physics, Multidisciplinary

WOS:000484374000016

NATURE PUBLISHING GROUP

20193107260678

Band structure ; Crystal lattices ; Optical lattices ; Textures

Laser Beam Interactions:744.8 ; Combinatorial Mathematics, Includes Graph Theory, Set Theory:921.4 ; Solid State Physics:933 ; Crystal Lattice:933.1.1

Web of Science

1.Hong Kong Univ Sci & Technol, Dept Phys, Hong Kong, Peoples R China
2.Peking Univ, Int Ctr Quantum Mat, Sch Phys, Beijing, Peoples R China
3.Collaborat Innovat Ctr Quantum Matter, Beijing, Peoples R China
4.Univ Chinese Acad Sci, CAS Ctr Excellence Topol Quantum Computat, Beijing, Peoples R China
5.Southern Univ Sci & Technol, Inst Quantum Sci & Engn, Shenzhen, Peoples R China
6.Southern Univ Sci & Technol, Dept Phys, Shenzhen, Peoples R China

Song, Bo,He, Chengdong,Niu, Sen,et al. Observation of nodal-line semimetal with ultracold fermions in an optical lattice[J]. Nature Physics,2019,15(9):911-+.

Song, Bo.,He, Chengdong.,Niu, Sen.,Zhang, Long.,Ren, Zejian.,...&Jo, Gyu-Boong.(2019).Observation of nodal-line semimetal with ultracold fermions in an optical lattice.Nature Physics,15(9),911-+.

Song, Bo,et al."Observation of nodal-line semimetal with ultracold fermions in an optical lattice".Nature Physics 15.9(2019):911-+.