论文标题
非热量子力学中的纠缠和净化过渡
Entanglement and purification transitions in non-Hermitian quantum mechanics
论文作者
论文摘要
经受连续测量和选择后的量子系统会根据非热汉尔顿剂的发展而演变。我们表明，随着人们提高选拔后的速度，这种非热汉尔顿族人经历了光谱相变。在这种相变的一侧（对于弱点后），最初混合密度矩阵始终混合在一起，最初未进入状态会形成体积法律纠缠。另一方面，任意的初始状态接近纠缠较低的独特纯状态。我们确定了在非铁族哈密顿量的频谱中具有特殊点的过渡，在该谱图中，PT对称性自发折断。我们表征了使用精确的对角线化和近似，可分析的均值平均场理论在混合阶段出现的过渡和非平凡稳态。这些方法得出一致的结论。
A quantum system subject to continuous measurement and post-selection evolves according to a non-Hermitian Hamiltonian. We show that, as one increases the rate of post-selection, this non-Hermitian Hamiltonian undergoes a spectral phase transition. On one side of this phase transition (for weak post-selection) an initially mixed density matrix remains mixed at all times, and an initially unentangled state develops volume-law entanglement; on the other side, an arbitrary initial state approaches a unique pure state with low entanglement. We identify this transition with an exceptional point in the spectrum of the non-Hermitian Hamiltonian, at which PT symmetry is spontaneously broken. We characterize the transition as well as the nontrivial steady state that emerges at late times in the mixed phase using exact diagonalization and an approximate, analytically tractable mean-field theory; these methods yield consistent conclusions.
