近日，北京大学的周小计及其研究小组与奥地利维也纳理工大学的Chen Li等人合作并取得一项新进展。经过不懈努力，他们对强相互作用分子玻色-爱因斯坦凝聚体的时间泰伯干涉仪进行研究。相关研究成果已于2024年4月15日在国际知名学术期刊《物理评论A》上发表。

本研究从实验和理论两方面研究了一维光学晶格中与⁶Li₂分子玻色-爱因斯坦凝聚体相互作用的泰伯干涉仪中相互作用的影响，相互作用强度可通过磁费什巴赫共振直接调节。研究人员观察到信号恢复的周期和幅度与相互作用强度之间存在显著的依赖关系。

尽管相互作用会加速信号的衰减并促进恢复过程，但研究发现在广泛的相互作用范围内，泰伯干涉仪在特定的演化时间尺度上依然保持高效性，这一结论同样适用于分数泰伯干涉的情况。本项工作不仅深化了对相互作用与光学晶格中时间泰伯干涉相干特性之间交互作用的理解，更为研究强相互作用系统中的量子干涉现象铺平了道路。

据悉，泰伯干涉仪作为时域动量分布的周期性再现，在多种研究中有着重要的应用。在衍射和干涉过程中粒子间的相互作用引入了许多多体物理问题，导致了非常规的干涉特性。

附：英文原文

Title: Temporal Talbot interferometer of a strongly interacting molecular Bose-Einstein condensate

Author: Fansu Wei, Zhengxi Zhang, Yuying Chen, Hongmian Shui, Yun Liang, Chen Li, Xiaoji Zhou

Issue&Volume: 2024/04/15

Abstract: The Talbot interferometer, as a periodic reproduction of momentum distribution in the time domain, finds significant applications in multiple research. The interparticle interactions during the diffraction and interference process introduce numerous many-body physics problems, leading to unconventional interference characteristics. This work investigates both experimentally and theoretically the influence of interaction in a Talbot interferometer with a ⁶Li₂ molecular Bose-Einstein condensate in a one-dimensional optical lattice, with interaction strength directly tunable via magnetic Feshbach resonance. A clear dependence of the period and amplitude of signal revivals on the interaction strength can be observed. While interactions increase the decay rate of the signal and advance the revivals, we find that over a wide range of interactions, the Talbot interferometer remains highly effective over a certain evolutionary timescale, including the case of fractional Talbot interference. This work provides insight into the interplay between interaction and the coherence properties of a temporal Talbot interference in optical lattices, paving the way for research into quantum interference in strongly interacting systems.

DOI: 10.1103/PhysRevA.109.043313

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.043313