论文标题
在具有短时动力学的自旋系统的量子模拟器中探测有限温度的可观察物
Probing finite-temperature observables in quantum simulators of spin systems with short-time dynamics
论文作者
论文摘要
在光学镊子中的自旋系统的量子模拟器中制备有限温度状态，例如被困的离子或rydberg原子，由于它们与环境几乎完美的隔离，因此具有挑战性。在这里，我们展示了如何通过jarzynski平等动机的算法获得有限的观测值，并且等同于Lu，Banuls和Cirac中的算法，PRX Quantum 2，020321（2021）。它包括对初始状态的经典重要性采样以及用量子模拟器对loschmidt回波的测量。我们将该方法用作量子启发的经典算法，并使用矩阵乘积状态模拟协议以分析量子模拟器上的需求。这样，我们表明在远程横向场ISING模型中可以在捕获的离子量子模拟器中表征有限温度相变。我们为Loschmidt Echo提出了一个具体的测量方案，并讨论了测量噪声，逐步降低以及状态准备和测量误差的影响。我们认为，在现实条件下，该算法对这些不完美是有力的。
Preparing finite temperature states in quantum simulators of spin systems, such as trapped ions or Rydberg atoms in optical tweezers, is challenging due to their almost perfect isolation from the environment. Here, we show how finite-temperature observables can be obtained with an algorithm motivated from the Jarzynski equality and equivalent to the one in Lu, Banuls and Cirac, PRX Quantum 2, 020321 (2021). It consists of classical importance sampling of initial states and a measurement of the Loschmidt echo with a quantum simulator. We use the method as a quantum-inspired classical algorithm and simulate the protocol with matrix product states to analyze the requirements on a quantum simulator. This way, we show that a finite temperature phase transition in the long-range transverse field Ising model can be characterized in trapped ion quantum simulators. We propose a concrete measurement protocol for the Loschmidt echo and discuss the influence of measurement noise, dephasing, as well as state preparation and measurement errors. We argue that the algorithm is robust against those imperfections under realistic conditions.
