Measurement of interacting quantum phases:A band mapping scheme  

作　　者：Qi Huang Zijie Zhu Yifei Wang Libo Liang Qinpei Zheng Xuzong Chen 

机构地区：[1]School of Electronics,Peking University,Beijing 100871,China [2]Institute for Quantum Electronics,ETH Zurich,8093 Zurich,Switzerland [3]Institute for Advanced Study,Tsinghua University,Beijing 100084,China

出　　处：《Frontiers of physics》2023年第5期193-199,共7页物理学前沿(英文版)

基　　金：supported by the National Key Research and Development Program of China(No.2021YFA1400900).

摘　　要：Band mapping is widely used in various scenarios of cold atom physics to measure the quasi-momentum distribution and band population.However,conventional methods fail in strongly interacting systems.Here we propose and experimentally realize a novel scheme of band mapping that can accurately measure the quasi-momentum of interacting manybody systems.Through an anisotropic control in turning down the threedimensional optical lattice,we can eliminate the effect of interactions on the band mapping process.Then,based on a precise measurement of the quasi-momentum distribution,we introduce the incoherent fraction as a physical quantity that can quantify the degree of incoherence of quantum many-body states.This method enables precise measurement of processes such as the superfluid to Mott insulator phase transition.Additionally,by analyzing the spatial correlation derived from the quasi-momentum of superfluid-Mott insulator phase transitions,we obtain results consistent with the incoherent fraction.Our scheme broadens the scope of band mapping and provides a method for studying quantum many-body problems.

关 键 词：ultracold physics Mott insulator SUPERFLUID band mapping 

分 类 号：O413[理学—理论物理]