基于动力学平均场的光晶格超冷原子量子模拟  

Quantum simulation of ultracold atoms in optical lattice based on dynamical mean-field theory

作　　者：谭辉 曹睿 李永强[1,2] Tan Hui;Cao Rui;Li Yong-Qiang(College of Science,National University of Defense Technology,Changsha 410073,China;Hunan Key Laboratory of Extreme Matter and Applications,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学理学院,长沙410073 [2]国防科技大学,极端条件物理与应用湖南省重点实验室,长沙410073

出　　处：《物理学报》2023年第18期19-36,共18页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12074431,12374252);湖南省杰出青年科学基金(批准号:2021JJ10044)资助的课题。

摘　　要：随着原子冷却技术与光晶格技术的发展,光晶格与超冷原子气体组成的量子系统已经成为量子模拟中的有力工具.光晶格纯净和高度可控的性质赋予其强大的调控能力,如今,人们可以模拟更复杂和有趣的物理现象,从而加深对量子多体物理的认识.本文综述了近年来本课题组利用玻色动力学平均场理论对强关联区间的光晶格玻色体系进行的一系列研究,包括多组分玻色体系、高轨道玻色体系以及存在长程相互作用的体系等.通过玻色动力学平均场理论的计算,揭示了从弱相互作用区间到强相互作用区间出现的丰富物理现象,包括不同磁序的量子相、多步凝聚、超固体相以及高轨道体系中的自旋-角动量耦合和阻挫效应.With the development of atomic cooling technology and optical lattice technology,the quantum system composed of optical lattice and ultracold atomic gas has become a powerful tool for quantum simulation.The purity and highly controllable nature of the optical lattice give it a strong regulatory capability.Therefore,more complex and interesting physical phenomena can be simulated,which deepens the understanding of quantum many-body physics.In recent years,we have studied different Bose systems with strong correlations in optical lattice based on the bosonic dynamical mean-field theory,including multi-component system,high-orbit bosonic system,and long-range interaction system.In this review,we introduce the research progress of the above mentioned.Through the calculation by using bosonic dynamical mean-field theory which has been generalized to multi-component and real space versions,a variety of physical phenomena of optical crystal lattice Bose system in weak interaction intervals to strong interaction intervals can be simulated.The phase diagram of spin-1 ultracold bosons in a cubic optical lattice at zero temperature and finite temperature are drawn.A spin-singlet condensate phase is found,and it is observed that the superfluid can be heated into a Mott insulator with even(odd)filling through the first(second)phase transition.In the presence of a magnetic field,the ground state degeneracy is broken,and there are very rich quantum phases in the system,such as nematic phase,ferromagnetic phase,spin-singlet insulating phase,polar superfluid,and broken-axisymmetry superfluid.In addition,multistep condensations are also observed.Further,we calculate the zero-temperature phase diagram of the mixed system of spin-1 alkali metal atoms and spin-0 alkali earth metal atoms,and find that the system exhibits a non-zero magnetic ordering,which shows a second-order Mott insulation-superfluid phase transition when the filling number is n=1,and a first-order Mott insulation-superfluid phase transition when the filling number i

关 键 词：冷原子量子模拟 玻色动力学平均场理论 量子相变 

分 类 号：O413[理学—理论物理]