Efficient computation of quantum time-optimal control

TL;DR

This paper introduces an efficient method combining quantum brachistochrone and Lax pair techniques to compute time-optimal control in large-scale quantum systems, demonstrated on a qubit lattice.

Contribution

The paper presents a novel approach that enables efficient calculation of quantum time-optimal control for large systems, integrating two advanced mathematical techniques.

Findings

Successfully computed the fastest excitation transfer in a large qubit lattice.

Demonstrated the method's efficiency for large-scale quantum systems.

Provided insights into optimal control strategies for quantum information processing.

Abstract

We present an approach to compute time-optimal control of a quantum system which combines quantum brachistochrone and Lax pair techniques and enables efficient investigation of large-scale quantum systems. We illustrate our method by finding the fastest way to transfer a single-particle excitation in a nearest-neighbor-coupled infinitely large qubit lattice with the fixed sum of squares of the couplings.