论文标题
近似密度运算符的长时间平均值：对角集合
Approximating the long time average of the density operator: Diagonal ensemble
论文作者
论文摘要
对于以平衡为单位的孤立的通用量子系统，对角线合奏的长时间平均值，即能量本征态概率与初始状态相同的混合状态，但在不同能量之间没有连贯性。在这项工作中，我们提出了一种使用张量网络近似对角线集合的方法。我们没有模拟实时演变，而是调整了[Phys]早期介绍的过滤方案。 Rev. B 101，144305（2020）]解决了这个问题。我们分析了该方法在不可融合的自旋链上的性能，为此我们观察到，局部可观察物与滤波器的逆宽度在多个金属上趋于热值。
For an isolated generic quantum system out of equilibrium, the long time average of observables is given by the diagonal ensemble, i.e. the mixed state with the same probability for energy eigenstates as the initial state but without coherences between different energies. In this work we present a method to approximate the diagonal ensemble using tensor networks. Instead of simulating the real time evolution, we adapt a filtering scheme introduced earlier in [Phys. Rev. B 101, 144305 (2020)] to this problem. We analyze the performance of the method on a non-integrable spin chain, for which we observe that local observables converge towards thermal values polynomially with the inverse width of the filter.
