Differentiable Quantum Computing for Large-scale Linear Control
This addresses the demand for efficient control in industrial models, offering a novel quantum approach with provable advantage, though it is domain-specific to linear control.
The paper tackles the problem of optimal control for large-scale dynamical systems by introducing an end-to-end quantum algorithm for linear-quadratic control, achieving a super-quadratic speedup compared to classical methods.
As industrial models and designs grow increasingly complex, the demand for optimal control of large-scale dynamical systems has significantly increased. However, traditional methods for optimal control incur significant overhead as problem dimensions grow. In this paper, we introduce an end-to-end quantum algorithm for linear-quadratic control with provable speedups. Our algorithm, based on a policy gradient method, incorporates a novel quantum subroutine for solving the matrix Lyapunov equation. Specifically, we build a quantum-assisted differentiable simulator for efficient gradient estimation that is more accurate and robust than classical methods relying on stochastic approximation. Compared to the classical approaches, our method achieves a super-quadratic speedup. To the best of our knowledge, this is the first end-to-end quantum application to linear control problems with provable quantum advantage.