论文标题
非热量子系统中的混合度时间尺度
Mixedness timescale in non-Hermitian quantum systems
论文作者
论文摘要
我们讨论了有限维量子系统的线性熵的短时扰动膨胀，该系统可以通过非热汉密尔顿人有效地描述动力学。我们为经历非热动力学的输入状态的混合性程度得出了一个时间尺度，并在驱动的两级系统的情况下对这些结果进行了专业化。接下来，我们为双方量子系统的混合性增长提供了一个时间尺度，该系统取决于有效的非富米汉顿式化学。在Hermitian限制中，该结果恢复了Hermitian系统中相干损失的扰动扩展，而它为初始纯和不相关的状态提供了纠缠时间范围。为了说明这些发现，我们考虑了多体横向场$ xy $ hamiltonian耦合到一个虚构的全面模型。我们发现，非热汉密尔顿人可以增强所考虑的输入状态的线性熵的短时动力学。总体而言，每个时间尺度都取决于最小成分，例如探针状态和该系统的非热汉密尔顿人，其评估需要较低的计算成本。我们的结果发现了应用于非铁量子量子传感的应用，非铁系统的量子热力学以及$ \ Mathcal {pt} $ - 对称量子场理论。
We discuss the short-time perturbative expansion of the linear entropy for finite-dimensional quantum systems whose dynamics can be effectively described by a non-Hermitian Hamiltonian. We derive a timescale for the degree of mixedness for an input state undergoing non-Hermitian dynamics and specialize these results in the case of a driven-dissipative two-level system. Next, we derive a timescale for the growth of mixedness for bipartite quantum systems that depends on the effective non-Hermitian Hamiltonian. In the Hermitian limit, this result recovers the perturbative expansion for coherence loss in Hermitian systems, while it provides an entanglement timescale for initial pure and uncorrelated states. To illustrate these findings, we consider the many-body transverse-field $XY$ Hamiltonian coupled to an imaginary all-to-all Ising model. We find that the non-Hermitian Hamiltonian enhances the short-time dynamics of the linear entropy for the considered input states. Overall, each timescale depends on minimal ingredients such as the probe state and the non-Hermitian Hamiltonian of the system, and its evaluation requires low computational cost. Our results find applications to non-Hermitian quantum sensing, quantum thermodynamics of non-Hermitian systems, and $\mathcal{PT}$-symmetric quantum field theory.
