论文标题
受绝热驾驶启发的多体基础准备的强化学习
Reinforcement Learning for Many-Body Ground-State Preparation Inspired by Counterdiabatic Driving
论文作者
论文摘要
量子交替的操作员ANSATZ(QAOA)是变异量子算法的突出例子。我们提出了一个名为CD-QAOA的广义QAOA,该QAOA的灵感来自反绝热驾驶程序,该程序设计用于量子多体系统,并使用增强学习(RL)方法进行了优化。所得的杂交控制算法证明了通过最小化能量来制备量子 - 融合多体旋转链的基础状态的多功能。我们表明,使用在绝热规格电位中发生的术语作为其他控制单位的发电机,可以实现快速的高保真性多体控制远离绝热制度。虽然每个统一都保留了常规的QAOA Intrinsic连续控制自由度(例如阶段持续时间),但我们将出现在控制序列中的多个可用单位的顺序视为附加的离散优化问题。我们将策略梯度算法赋予自动回归深度学习体系结构,以捕获因果关系,我们训练RL代理以构建最佳的单位序列。该算法无法访问量子状态,我们发现在小型系统上学习的协议可能会推广到较大的系统。通过扫描一系列协议持续时间,我们提供了数值证据,证明在不可集成的混合场旋转1/2 ISING和Lipkin-Meshkov-Glick模型中具有有限的量子速度限制,以及适合在长期和拓扑订购的参数参数方案中准备Spin-1 Heisenberg链的地面状态。这项工作铺平了为量子多体控制目的而从深度学习中纳入最新成功的方式。
The quantum alternating operator ansatz (QAOA) is a prominent example of variational quantum algorithms. We propose a generalized QAOA called CD-QAOA, which is inspired by the counterdiabatic driving procedure, designed for quantum many-body systems and optimized using a reinforcement learning (RL) approach. The resulting hybrid control algorithm proves versatile in preparing the ground state of quantum-chaotic many-body spin chains by minimizing the energy. We show that using terms occurring in the adiabatic gauge potential as generators of additional control unitaries, it is possible to achieve fast high-fidelity many-body control away from the adiabatic regime. While each unitary retains the conventional QAOA-intrinsic continuous control degree of freedom such as the time duration, we consider the order of the multiple available unitaries appearing in the control sequence as an additional discrete optimization problem. Endowing the policy gradient algorithm with an autoregressive deep learning architecture to capture causality, we train the RL agent to construct optimal sequences of unitaries. The algorithm has no access to the quantum state, and we find that the protocol learned on small systems may generalize to larger systems. By scanning a range of protocol durations, we present numerical evidence for a finite quantum speed limit in the nonintegrable mixed-field spin-1/2 Ising and Lipkin-Meshkov-Glick models, and for the suitability to prepare ground states of the spin-1 Heisenberg chain in the long-range and topologically ordered parameter regimes. This work paves the way to incorporate recent success from deep learning for the purpose of quantum many-body control.