Superadiabatic Control of Quantum Operations

TL;DR

This paper introduces a superadiabatic control method for quantum operations that enhances robustness and fidelity by systematically designing pulses based on the superadiabatic Q-factor, applicable to single and multi-qubit systems.

Contribution

The paper presents a new superadiabatic control approach using the Q-factor as a performance metric, enabling systematic design of robust, high-fidelity quantum control pulses for single and multi-qubit operations.

Findings

Superadiabatic pulses show improved robustness to control errors.

A numerical search strategy for adiabatic unitaries is developed.

Control waveforms for a two-qubit entangling gate are successfully designed.

Abstract

Adiabatic pulses are used extensively to enable robust control of quantum operations. We introduce a new approach to adiabatic control that uses the superadiabatic quality or $Q$-factor as a performance metric to design robust, high fidelity pulses. This approach permits the systematic design of quantum control schemes to maximize the adiabaticity of a unitary operation in a particular time interval given the available control resources. The interplay between adiabaticity, fidelity and robustness of the resulting pulses is examined for the case of single-qubit inversion, and superadiabatic pulses are demonstrated to have improved robustness to control errors. A numerical search strategy is developed to find a broader class of adiabatic operations, including multi-qubit adiabatic unitaries. We illustrate the utility of this search strategy by designing control waveforms that adiabatically implement a two-qubit entangling gate for a model NMR system.