玻色凝聚原子在宇称-时间对称势中的多体量子动力学

Parity-time (PT) symmetry, the invariance under parity-time reflection, is an important concept in quantum physics. Attribute their robust quantum coherence and hight contrallability, ultra Bose condensed atomic gases provide a new platform for exploring quantum property and dynamics of PT symmetric many-body quantum system. Based upon non-Hermitian Hamiltonian described open quantum system, we investigate many-body quantum dynamics and quantum manipulation of Bose condensed atoms confined in PT symmetric potential. Applying both analytical and numerical approaches, we will analyse the time evolution of their quantum state, and reveal PT symmetry how to affect many-body quantum coherence, quantum entanglement, many-body Landau-Zener process and quantum interference. Furthermore, we will study, under periodic driven field, its many-body quantum dynamics and quantum manipulation, explore the effect of PT symmetry on many-body quantum tunnelling and chaotic dynamics, and search efficient approaches for manipulating PT symmetry of PT symmetric many-body quantum system. The researchs on PT symmetric many-body quantum system will not only broaden our understanding of open quantum theory, many-body quantum physics and chaos, but also will provide theoretical reference for the development of manipulation of open quantum system and its practical application.

宇称-时间(PT)对称性，即空间反射和时间反演下的不变性，是量子物理中一个重要的基本问题。由于具有稳固的量子相干性和高度的可控性，超冷玻色凝聚原子气体为研究PT对称多体量子系统的量子特性及其动力学行为提供了一个新平台。基于开放量子体系的非厄密描述，本项目研究玻色凝聚原子在PT对称势中的多体量子动力学现象及其调控。解析分析结合数值模拟,分析相关多体量子态的时间演化，揭示PT对称性对多体量子相干、量子纠缠、多体Landau-Zener过程以及量子干涉的影响，研究周期驱动下的多体量子动力学行为及其调控，探索PT对称性对多体量子隧穿以及混沌动力学的影响，搜寻利用驱动外场去调控PT对称多体量子体系PT对称性的方法。PT对称多体量子体系的研究不仅将增进我们对开放量子理论、多体量子物理以及混沌理论之中的相关现象和原理的理解，而且也将为开放量子体系调控技术的发展和实际应用提供理论参考。

我们主要研究了时间周期调制PT对称势中玻色凝聚原子的多体量子动力学及PT对称性的调控，发展了处理PT对称势中玻色凝聚原子体系的理论和数值方法，提出了PT对称性的周期调制方法,揭示了体系某些多体量子动力学所服从的基本规律,探索了调控体系多体量子态的新手段。代表性的工作有：(1)利用周期调制去调节开放多体量子体系的PT对称性；(2) 发现了多体Landau-Zener过程中的边带跃迁。在本项目的支持下，共完成项目SCI论文15篇，其中Phys. Rev. A论文4篇。有关利用周期调制调控PT 对称性的理论预言被实验证实。