Title: Driving of an open quantum system at finite temperature across first- and second-order quantum phase transitions Show Chinese title

Title: 在有限温度下驱动开放量子系统穿越一阶和二阶量子相变

Abstract: An open fully connected system of qubits at nonzero temperature is driven within a finite time interval along various paths in the space of its control parameters.The driving leads across finite-size precursors of first- and second-order quantum phase transition from factorized to entangled ground-state phases, aiming at the preparation of the complex ground state of the system at the final parameter point with maximal fidelity.During the drive, the system is coupled to a heat bath at a constant temperature, the dynamics being determined in a nonperturbative way by the method of Hierarchical Equations of Motion. It is shown that the presence of the heat bath in combination with specific patterns of avoided crossings affecting the ground and excited states in the parameter region around the quantum phase transition may considerably improve the fidelity of preparation of the target ground state. Show Chinese abstract

Abstract: 在非零温度下，一个开放的全连接量子比特系统在控制参数空间中沿各种路径在有限时间间隔内被驱动。这种驱动跨越了从因子化到纠缠基态相的第一和第二阶量子相变的有限尺寸前驱现象，旨在以最大保真度准备最终参数点处系统的复杂基态。在驱动过程中，系统与恒温热库耦合，动力学由运动方程的层次方法以非微扰方式确定。 结果显示，热库的存在结合特定的回避交叉模式，在量子相变区域影响基态和激发态，可能会显著提高目标基态制备的保真度。