论文标题
使用还原级建模控制量子多体系统
Controlling quantum many-body systems using reduced-order modelling
论文作者
论文摘要
由于相关潜在问题的计算复杂性,量子多体控制是量子科学中最具挑战性的问题之一。我们提出了一种有效的方法来解决多体量子系统的一类控制问题,其中将时间依赖性控制应用于足够小的子系统。该方法基于基于张量 - 网络的方案,该方案构建了子系统非马克维亚动力学的低维还原模型。 Simulating dynamics of such a reduced-order model, viewed as a ``digital twin" of the original subsystem, is significantly more efficient, which enables the use of gradient-based optimization toolbox in the control parameter space. We validate the proposed method by solving control problems for quantum spin chains. In particular, the approach automatically identifies sequences for exciting the quasiparticles and guiding their dynamics to recover and transmit information. Additionally, when disorder被诱导并在许多身体局部阶段中,我们发现动态反演的旋转回波序列与标准方法相比,该序列的性能得到了改善。多体系统,在探测非平凡的准粒子特性以及用于量子计算设备的开发控制工具中。
Quantum many-body control is among most challenging problems in quantum science, due to computational complexity of related underlying problems. We propose an efficient approach for solving a class of control problems for many-body quantum systems, where time-dependent controls are applied to a sufficiently small subsystem. The approach is based on a tensor-networks-based scheme to build a low-dimensional reduced-order model of the subsystem's non-Markovian dynamics. Simulating dynamics of such a reduced-order model, viewed as a ``digital twin" of the original subsystem, is significantly more efficient, which enables the use of gradient-based optimization toolbox in the control parameter space. We validate the proposed method by solving control problems for quantum spin chains. In particular, the approach automatically identifies sequences for exciting the quasiparticles and guiding their dynamics to recover and transmit information. Additionally, when disorder is induced and the system is in the many body localized phase, we find generalized spin-echo sequences for dynamics inversion, which show improved performance compared to standard ones. Our approach by design takes advantage of non-Markovian dynamics of a subsystem to make control protocols more efficient, and, under certain conditions can store information in the rest of the many-body system and subsequently retrieve it at a desired moment of time. We expect that our results will find direct applications in the study of many-body systems, in probing non-trivial quasiparticle properties, as well as in development control tools for quantum computing devices.