Robust Control of High-dimensional Quantum Systems against Coherent and Incoherent Errors

TL;DR

This paper introduces a systematic framework for robust control of high-dimensional quantum systems, effectively handling both coherent and incoherent errors to enhance control design efficiency and scalability.

Contribution

It reformulates robust quantum control as an optimal control problem using Taylor series and Suzuki-Trotter expansion, enabling efficient handling of high-dimensional systems.

Findings

Successfully identifies robust solutions in multi-qubit systems.

Extends the feasibility of high-order robust control for complex quantum systems.

Demonstrates improved control design efficiency through numerical simulations.

Abstract

Toward scalable quantum computing, the control of quantum systems needs to be robust against both coherent errors induced by parametric uncertainties and incoherent errors induced by environmental decoherence. This poses significant challenges for high-dimensional systems due to the computational intensity involved in the control design process. In this paper, we propose a systematic framework to improve the design efficiency. By employing the Taylor series expansion of uncertain parameters, the problem of robust control for an uncertain quantum system is reformulated as the optimal control problem of an augmented deterministic system. The Suzuki-Trotter expansion is then applied to accelerate the calculation of the system dynamics. Numerical simulations of quantum state preparation and quantum gate synthesis demonstrate that the proposed algorithm can successfully identify robust solutions in multi-qubit systems. The enhanced efficiency effectively extends the feasibility of high-order robust control for realistic high-dimensional quantum systems with multiple error sources.