论文标题
固定点量子蒙特卡洛
Fixed Point Quantum Monte Carlo
论文作者
论文摘要
我们为多体量子物理学中的平衡特性研究提供了一种新的方法。我们的方法从密度矩阵量子蒙特卡洛（Monte Carlo）汲取灵感，并具有新的关键特征。首先，将动力学传输到拉普拉斯表示，在该拉普拉斯表示中，可以使用模拟步骤得出和求解精确的方程式，而与大多数蒙特卡洛方法不同，它不是先验的物理界限。此外，产卵事件是根据量子大师方程式的两个过程随机分开来制定的，这种形式主义在使用密度矩阵时特别有用。最后，这等同于相互作用图片，在相互作用图片中，自由零件被精确整合在一起，如果相互作用参数很小，则可以大大提高收敛速率。我们通过将其应用于凝结物理学的两个案例研究，显示其准确性并进一步讨论其效率来基准我们的方法。
We present a new approach to the study of equilibrium properties in many-body quantum physics. Our method takes inspiration from Density Matrix Quantum Monte Carlo and incorporates new crucial features. First of all, the dynamics is transferred to the Laplace representation where an exact equation can be derived and solved using a simulation-step that, unlike most Monte Carlo methods, is not a priori physically bounded. Moreover, the spawning events are formulated in terms of two-process stochastic unravellings of quantum master equations, a formalism that is particularly useful when working with density matrices. And last, this is equivalent to an interaction picture, where the free part is integrated exactly and the convergence rate can be greatly increased if the interaction parameter is small. We benchmark our method by applying it to two case-studies in condensed matter physics, show its accuracy and further discuss its efficiency.
