近日，中国科学院物理研究所的刘伍明课题组与中国科学技术大学的邹旭波等人合作，研究了可调谐的玻色子辅助有限范围相互作用和在光学晶格中构建马约拉纳（Majorana）角模。相关成果已于2023年4月5日在国际学术期刊《物理评论A》上发表。

该研究团队提出了一种有效且可行的方案，用于在光学晶格中实现无自旋费米子与玻色子浴之间的可调有限范围相互作用。通过操作玻色子，可以人为地调节费米子子系统的有效相互作用强度，从斥力到吸引力不等。此外，相互作用距离被锁定在玻色子的跃迁上，使得有限范围相互作用对于费米子子系统非常干净。

具体而言，研究团队发现，通过引入额外的玻色子交错跃迁，可以轻松地应用该方案在无自旋系统中寻找马约拉纳角模，而无需实现复杂的人造规范场。这与已报道的自旋系统的结果完全不同。因此，该方案为探索超冷原子中由长程相互作用引起的非传统拓扑超流体和其他非平凡相提供了潜在平台。

据悉，被俘获在光学晶格中的超冷原子之间的非局域相互作用可以引起有趣的量子多体现象。然而，其实现通常需要非传统技术，例如人造规范场或高轨道费什巴赫共振，并且不太可控。

附：英文原文

Title: Tunable boson-assisted finite-range interaction and engineering Majorana corner modes in optical lattices

Author: Yu-Biao Wu, Zhen Zheng, Xiang-Gang Qiu, Lin Zhuang, Guang-Can Guo, Xu-Bo Zou, Wu-Ming Liu

Issue&Volume: 2023/04/05

Abstract: Nonlocal interaction between ultracold atoms trapped in optical lattices can give rise to interesting quantum many-body phenomena. However, its realization usually demands unconventional techniques, for example, the artificial gauge fields or higher-orbit Feshbach resonances, and is not highly controllable. Here, we propose a valid and feasible scheme for realizing a tunable finite-range interaction for spinless fermions immersed into the bath of bosons. The strength of the effective interaction for the fermionic subsystem is artificially tunable by manipulating bosons, ranging from the repulsive to the attractive regime. In addition, the interaction distance is locked to the hopping of bosons, making the finite-range interaction perfectly clean for the fermionic subsystem. Specifically, we find that, by introducing an additional staggered hopping of bosons, the proposal is readily applied to search the Majorana corner modes in such a spinless system, without the implementation of complex artificial gauge fields, which is totally distinct from existing results reported in spinful systems. Therefore, this scheme provides a potential platform for exploring the unconventional topological superfluids and other nontrivial phases induced by long-range interactions in ultracold atoms.

DOI: 10.1103/PhysRevA.107.043304

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.107.043304