论文标题
观察费米 - 哈伯德模型中电荷和自旋的分离动力学
Observation of separated dynamics of charge and spin in the Fermi-Hubbard model
论文作者
论文摘要
密切相关的量子系统会引起许多异国情调的物理现象，包括高温超导性。在量子计算机上模拟这些系统可能会避免经典方法产生的高度高计算成本。但是，当前量子设备中呈现的系统错误和变形效应使得难以实现这一目标。在这里，我们使用数字超导量子处理器上的16个Quinbits模拟了一维费米 - 哈伯德模型的动力学。我们观察到高度激发式的电荷和自旋密度的扩散速度的分离，这是超出常规准粒子图片的策略。为了最大程度地减少系统错误，我们引入了一个准确的门校准过程，该过程足够快，可以捕获门参数的时间漂移。我们还采用了一系列误差技术来减少破坏性效应和残留的系统错误。这些程序使我们能够忠实地模拟该模型的时间演变，尽管我们的电路中有超过600个两倍的大门。我们的实验图表了使用可用的量子设备对强相关现象进行实用量子模拟的一条途径。
Strongly correlated quantum systems give rise to many exotic physical phenomena, including high-temperature superconductivity. Simulating these systems on quantum computers may avoid the prohibitively high computational cost incurred in classical approaches. However, systematic errors and decoherence effects presented in current quantum devices make it difficult to achieve this. Here, we simulate the dynamics of the one-dimensional Fermi-Hubbard model using 16 qubits on a digital superconducting quantum processor. We observe separations in the spreading velocities of charge and spin densities in the highly excited regime, a regime that is beyond the conventional quasiparticle picture. To minimize systematic errors, we introduce an accurate gate calibration procedure that is fast enough to capture temporal drifts of the gate parameters. We also employ a sequence of error-mitigation techniques to reduce decoherence effects and residual systematic errors. These procedures allow us to simulate the time evolution of the model faithfully despite having over 600 two-qubit gates in our circuits. Our experiment charts a path to practical quantum simulation of strongly correlated phenomena using available quantum devices.
