Rescaling interactions for quantum control

TL;DR

This paper introduces a linear programming-based algorithm for rescaling quantum interactions, enabling precise control over Hamiltonian terms in large-scale quantum systems for improved quantum computing operations.

Contribution

It presents a novel algorithm for time-optimal rescaling of interactions in multi-qubit systems, extending control capabilities beyond traditional spin echo techniques.

Findings

Efficient rescaling solutions for systems of tens of qubits.

Near time-optimal solutions for systems with hundreds of qubits.

Enhanced control over internal Hamiltonians in quantum computing.

Abstract

A powerful control method in experimental quantum computing is the use of spin echoes, employed to select a desired term in the system's internal Hamiltonian, while refocusing others. Here we address a more general problem, describing a method to not only turn on and off particular interactions but also to rescale their strengths so that we can generate any desired effective internal Hamiltonian. We propose an algorithm based on linear programming for achieving time-optimal rescaling solutions in fully coupled systems of tens of qubits, which can be modified to obtain near time-optimal solutions for rescaling systems with hundreds of qubits.