Robust nonadiabatic geometric quantum computation by dynamical correction

TL;DR

This paper introduces a robust nonadiabatic geometric quantum computation scheme that combines dynamical correction and decoherence-free subspace encoding, enhancing gate fidelity against control errors and noise, suitable for scalable quantum computing.

Contribution

It presents a new robust NGQC protocol using simplified pulses and dynamical correction, improving error resilience over previous methods.

Findings

Significantly improves gate robustness against control errors.

Incorporates decoherence-free subspace to combat dephasing noise.

Proposes implementation on superconducting circuits with current technology.

Abstract

Besides the intrinsic noise resilience property, nonadiabatic geometric phases are of the fast evolution nature, and thus can naturally be used in constructing quantum gates with excellent performance, i.e., the so-called nonadiabatic geometric quantum computation (NGQC). However, previous single-loop NGQC schemes are sensitive to the operational control error, i.e., the $X$ error, due to the limitations of the implementation. Here, we propose a robust scheme for NGQC combining with the dynamical correction technique, which still uses only simplified pulses, and thus being experimental friendly. We numerically show that our scheme can greatly improve the gate robustness in previous protocols, retaining the intrinsic merit of geometric phases. Furthermore, to fight against the dephasing noise, due to the $Z$ error, we can incorporate the decoherence-free subspace encoding strategy. In this way, our scheme can be robust against both types of errors. Finally, we also propose how to implement the scheme with encoding on superconducting quantum circuits with experimentally demonstrated technology. Therefore, due to the intrinsic robustness, our scheme provides a promising alternation for the future scalable fault-tolerant quantum computation.