基于超冷囚禁离子的量子相变临界行为的研究

量子相变是多体系统在量子涨落影响下的突变行为，是理解量子多体物理的一个重要课题。近年来，不同物理模型下的量子相变的理论和实验研究都取得了巨大的进展。本项目以囚禁的超冷离子体系为研究对象，研究量子相变中展现的量子基态对称性破缺、声子超辐射行为以及相关的多体量子关联，并探讨实验的可行性。主要内容包括：1）建立基于激光操控的离子少体体系的二阶量子相变理论模型，引入真实的实验参量做动力学分析；2）探讨量子相变导致的多体量子关联，定量估算量子关联，深入分析相变的临界行为与量子关联的内在联系；3）研究抑制系统退相干的方案，通过优化实验参数，更好地展现临界行为。本项目着眼于理论结合实验开展研究，将深化我们对离子体系量子性质的认识，发展新的操控量子态的方法，为实现超冷离子的大规模量子信息处理提供理论参考。

Quantum phase transition behaves as a sudden change under the influence of quantum fluctuation, which is an important subject for understanding quantum many-body physics. Quantum phase transition has achieved significant progress both theoretically and experimentally in different models over past years. The project focuses on the quantum phase transition in ultracold trapped ions, investigating symmetric breaking of the ground state, phononic superradiation and many-body quantum correlation as well as the experimental feasibility. The main contents include: 1) Establishing the second-order quantum phase transition model based on the laser-manipulated few-body trapped ions and analyzing dynamics using experimental parameters; 2) Exploring many-body quantum correlation induced by quantum phase transition, evaluating quantitatively quantum correlation and discussing intrinsic connection between critical behavior and quantum correlation; 3) Studying schemes for suppressing decoherence and optimizing experimental parameters for better demonstrating critical behavior. The project will proceed by combining theory with experimental progress, which will deepen our understanding for quantum properties of the ion system, develop new experimental approaches for quantum state control and help for achieving large-scale quantum information processing using trapped ions.