论文标题
广义基塔维尔模型的量子蒙特卡洛模拟
Quantum Monte Carlo Simulation of Generalized Kitaev Models
论文作者
论文摘要
沮丧的旋转系统通常会遭受蒙特卡洛方法固有的负符号问题。由于此问题的严重性取决于配方，因此可以提出优化策略。我们在辅助场量子卡洛算法的领域中引入了一种相位固定方法。如果我们能找到一个与辅助场相连的一个主体哈密顿人通勤的反独立操作员，那么该动作的阶段被固定在$ 0 $和$π$。对于广义的Kitaev模型，我们可以成功地采用此策略，并观察到平均符号的显着改善。我们使用这种方法来研究Kitaev-Heisenberg模型的热力学和动力学特性，以对应于一半交换耦合常数的温度。我们的动态数据揭示了该模型固有的有序温度和自旋液体相的有限温度性能。
Frustrated spin systems generically suffer from the negative sign problem inherent to Monte Carlo methods. Since the severity of this problem is formulation dependent, optimization strategies can be put forward. We introduce a phase pinning approach in the realm of the auxiliary field quantum Monte Carlo algorithm. If we can find an anti-unitary operator that commutes with the one body Hamiltonian coupled to the auxiliary field, then the phase of the action is pinned to $0$ and $π$. For generalized Kitaev models, we can successfully apply this strategy and observe a remarkable improvement of the average sign. We use this method to study thermodynamical and dynamical properties of the Kitaev-Heisenberg model down to temperatures corresponding to half of the exchange coupling constant. Our dynamical data reveals finite temperature properties of ordered and spin-liquid phases inherent to this model.
