Realization of^(87)Rb Bose–Einstein Condensates in Higher Bands of a Hexagonal Boron-Nitride Optical Lattice  

作　　者：刘金玉 王小琼 许志芳 Jin-Yu Liu;Xiao-Qiong Wang;Zhi-Fang Xu(Department of Physics,Harbin Institute of Technology,Harbin 150001,China;Department of Physics,Southern University of Science and Technology,Shenzhen 518055,China;Shenzhen Institute for Quantum Science and Engineering,Southern University of Science and Technology,Shenzhen 518055,China)

机构地区：[1]Department of Physics,Harbin Institute of Technology,Harbin 150001,China [2]Department of Physics,Southern University of Science and Technology,Shenzhen 518055,China [3]Shenzhen Institute for Quantum Science and Engineering,Southern University of Science and Technology,Shenzhen 518055,China

出　　处：《Chinese Physics Letters》2023年第8期53-57,共5页中国物理快报（英文版）

基　　金：supported by the National Key R&D Program of China(Grant Nos.2022YFA1404103,2018YFA0307200);the Key Area Research and Development Program of Guangdong Province(Grant No.2019B030330001);the National Natural Science Foundation of China(Grant No.12274196);Funds from Guangdong Province(Grant Nos.2019QN01X087,2019ZT08X324)。

摘　　要：Ultracold neutral atoms in higher bands of an optical lattice provide a natural avenue to emulate orbital physics in solid state materials.Here,we report the realization of^(87)Rb Bose-Einstein condensates in the fourth and seventh Bloch bands of a hexagonal boron-nitride optical lattice,exhibiting remarkably long coherence time through active cooling.Using band mapping spectroscopy,we observe that atoms condensed at the energy minimum of L point(K_(1)and K_(2)points)in the fourth(seventh)band as sharp Bragg peaks.The lifetime for the condensate in the fourth(seventh)band is about 57.6(4.8)ms,and the phase coherence of atoms in the fourth band persists for a long time larger than 110 ms.Our work thus offers great promise for studying unconventional bosonic superfluidity of neutral atoms in higher bands of optical lattices.

关 键 词：materials BANDS EINSTEIN 

分 类 号：O469[理学—凝聚态物理]