Robust Oscillator-Mediated Phase Gates Driven by Low-Intensity Pulses

TL;DR

This paper introduces a general dynamical decoupling-based method for faster, robust entanglement gates mediated by bosonic modes using low-intensity pulses, applicable across various quantum platforms.

Contribution

It presents a novel protocol enabling faster, more robust oscillator-mediated entanglement gates with low-intensity pulses, resistant to common experimental errors.

Findings

Achieves entanglement infidelity of 10^{-3} with current setups.

Demonstrates robustness against qubit frequency fluctuations and mediator heating.

Applicable to any platform with longitudinal qubit-boson coupling.

Abstract

Robust qubit-qubit interactions mediated by bosonic modes are central to many quantum technologies. Existing proposals combining fast oscillator-mediated gates with dynamical decoupling require strong pulses or fast control over the qubit-boson coupling. Here, we present a method based on dynamical decoupling techniques that leads to faster-than-dispersive entanglement gates with low-intensity pulses. Our method is general, i.e., it is applicable to any quantum platform that has qubits interacting with bosonic mediators via longitudinal coupling. Moreover, the protocol provides robustness to fluctuations in qubit frequencies and control fields, while also being resistant to common errors such as frequency shifts and heating in the mediator as well as crosstalk effects. We illustrate our method with an implementation for trapped ions coupled via magnetic field gradients. With detailed numerical simulations, we show that entanglement gates with infidelities of $10^{-3}$ or $10^{-4}$ are possible with current or near-future experimental setups, respectively.