中国上海大学张永平团队近日研究了自旋-轨道耦合塞曼晶格中玻色-爱因斯坦凝聚体的带边超流体。相关论文于2025年6月5日发表在《物理评论A》杂志上。

自从在自旋轨道耦合塞曼晶格中首次实验实现玻色-爱因斯坦凝聚以来，在这些系统中发现了广泛的应用。

研究组系统地研究了系统的基态相图。自旋轨道耦合的塞曼晶格在最低的布洛赫带产生多个能量极小值。这些极小值可能位于布里渊区边缘和中心，也可能位于布里渊区内部。相互作用的原子凝聚成这些最小值就构成了基态量子相。

在这些相中，带边凝聚态在自旋-轨道耦合的均质体系和没有自旋-轨道耦合的晶格体系中都没有相似之处。它们存在于自旋轨道耦合塞曼晶格体系的一个非常广泛的参数区。研究组通过分析带边态的初等激励和超流分数来解决带边态的超流动性问题。

附：英文原文

Title: Band-edge superfluid of Bose-Einstein condensates in the spin-orbit-coupled Zeeman lattice

Author: Huaxin He, Fengtao Pang, Hao Lyu, Yongping Zhang

Issue&Volume: 2025/06/05

Abstract: Since the first experimental realization of Bose-Einstein condensates in a spin-orbit-coupled Zeeman lattice, a wide range of applications have been found in these systems. Here, we systematically study the ground-state phase diagram of the systems. The spin-orbit-coupled Zeeman lattice generates multiple energy minima in the lowest Bloch band. These minima may locate at Brillouin-zone edges and center, or inside the Brillouin zone. Interacting atoms condensing into these minima constitute ground-state quantum phases. Among these phases, the band-edge condensation states have no analog in either spin-orbit-coupled homogeneous systems or lattice systems without the spin-orbit coupling. They exist in a very broad parameter regime of the spin-orbit-coupled Zeeman lattice system. We address superfluidity of the band-edge states by analyzing their elementary excitations and superfluid fraction.

DOI: 10.1103/PhysRevA.111.063305

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.063305