Engineered Robustness for Nonadiabatic Geometric Quantum Gates

TL;DR

This paper introduces a new framework for nonadiabatic geometric quantum gates that enhances robustness and fidelity, demonstrating significant improvements in single-qubit gates on superconducting qubits and analyzing two-qubit limitations.

Contribution

The authors develop a streamlined, super-robust framework for nonadiabatic geometric quantum gates with auxiliary constraints and noncyclic paths, improving practical robustness.

Findings

Single-qubit NGQGs achieve infidelity scaling as O(ε^4) against Rabi amplitude errors.

The scheme demonstrates high-fidelity, robust single-qubit gates on superconducting transmon qubits.

Two-qubit NGQGs face limitations due to phase and waveform calibration issues.

Abstract

While geometric quantum gates are often theorized to possess intrinsic resilience to control errors by exploiting the global properties of evolution paths, this promise has not consistently translated into practical robustness. We present a streamlined framework for nonadiabatic geometric quantum gates (NGQGs) that incorporates additional auxiliary constraints to suppress dynamical contamination and achieve super-robust performance. Within this framework, we also design NGQGs using noncyclic paths, offering enhanced design flexibility. Implemented on superconducting transmon qubits, our scheme realizes high-fidelity single-qubit gates that are robust against Rabi amplitude error $\epsilon$, with infidelity scaling as $\mathcal{O}(\epsilon^4)$, in contrast to the $\mathcal{O}(\epsilon^2)$ behavior of conventional dynamical gates. We further analyze two-qubit NGQGs under parametric driving. Our results identify subtle limitations that compromise performance in two-qubit scenarios, underscoring the importance of phase compensation and waveform calibration. The demonstrated simplicity and generality of our super-robust NGQG scheme make it applicable across diverse quantum platforms.