Robust and optimal control of open quantum systems

TL;DR

This paper presents an improved algorithm for robust and optimal control of open quantum systems, demonstrating enhanced scalability and lower infidelity in superconducting circuits, advancing practical quantum technology applications.

Contribution

The authors develop a scalable control algorithm that suppresses system imperfections in open quantum systems, validated experimentally with superior performance over traditional methods.

Findings

Achieved ultra-low infidelity of about 0.60% in superconducting circuits.

Enhanced scalability of the control algorithm with modest complexity increase.

Demonstrated practical applicability of the control method in quantum technologies.

Abstract

Recent advancements in quantum technologies have highlighted the importance of mitigating system imperfections, including parameter uncertainties and decoherence effects, to improve the performance of experimental platforms. However, most of the previous efforts in quantum control are devoted to the realization of arbitrary unitary operations in a closed quantum system. Here, we improve the algorithm that suppresses system imperfections and noises, providing notably enhanced scalability for robust and optimal control of open quantum systems. Through experimental validation in a superconducting quantum circuit, we demonstrate that our approach outperforms its conventional counterpart for closed quantum systems with an ultra-low infidelity of about $0.60\%$, while the complexity of this algorithm exhibits the same scaling, with only a modest increase in the prefactor. This work represents a notable advancement in quantum optimal control techniques, paving the way for realizing quantum-enhanced technologies in practical applications.