论文标题
一种有效的量子杂质问题的方法
An efficient method for quantum impurity problems out of equilibrium
论文作者
论文摘要
我们引入了一种有效的方法，以模拟与非相互作用的效费储层相互作用的量子杂质的动力学。将杂质视为开放量子系统，我们用Feynman-Vernon影响功能（如果）描述了储层。 IF表示为时间域中的矩阵 - 产物状态，这可以有效地计算用于任意相互作用的动力学。我们将我们的方法应用于安德森杂质模型中的量子淬火和运输，包括高度非平衡的设置，并与最新方法相比找到了有利的性能。精确计算动力学量表的计算资源在多项式时间内随着演变时间的多种多样而言，这表明一类广泛的平衡量子杂质问题可以有效地解决。这种方法将为介质设备和相关材料的动态特性提供新的见解。
We introduce an efficient method to simulate dynamics of an interacting quantum impurity coupled to non-interacting fermionic reservoirs. Viewing the impurity as an open quantum system, we describe the reservoirs by their Feynman-Vernon influence functionals (IF). The IF are represented as matrix-product states in the temporal domain, which enables an efficient computation of dynamics for arbitrary interactions. We apply our method to study quantum quenches and transport in an Anderson impurity model, including highly non-equilibrium setups, and find favorable performance compared to state-of-the-art methods. The computational resources required for an accurate computation of dynamics scale polynomially with evolution time, indicating that a broad class of out-of-equilibrium quantum impurity problems are efficiently solvable. This approach will provide new insights into dynamical properties of mesoscopic devices and correlated materials.
