论文标题
量子计算机上有限温度状态的变异制备
Variational preparation of finite-temperature states on a quantum computer
论文作者
论文摘要
热平衡状态的制备对于使用量子计算机模拟凝结物和宇宙系统很重要。我们提出了一种与单一操作员一起准备此类混合状态的方法，并使用基于门的量子处理器在实验中证明了这一技术。我们的方法使用由量子 - 容易发生优化算法促进的混合量子古典变异方法的生成，而没有通过数值模拟对最佳变异参数进行计算。生成状态对热平衡状态的忠诚度在无限和接近零模拟温度之间的99％到75％之间，与噪声量子处理器的数值模拟有关，并从实验中汲取了误差参数。
The preparation of thermal equilibrium states is important for the simulation of condensed-matter and cosmology systems using a quantum computer. We present a method to prepare such mixed states with unitary operators, and demonstrate this technique experimentally using a gate-based quantum processor. Our method targets the generation of thermofield double states using a hybrid quantum-classical variational approach motivated by quantum-approximate optimization algorithms, without prior calculation of optimal variational parameters by numerical simulation. The fidelity of generated states to the thermal-equilibrium state smoothly varies from 99 to 75% between infinite and near-zero simulated temperature, in quantitative agreement with numerical simulations of the noisy quantum processor with error parameters drawn from experiment.
