Robust two-qubit trapped ions gates using spin-dependent squeezing

TL;DR

This paper introduces a new method for two-qubit gates in trapped ion quantum computers that combines spin-dependent squeezing with displacement, significantly enhancing robustness against noise and amplitude deviations.

Contribution

The authors develop an analytical approach to engineer a robust two-qubit gate using spin-dependent squeezing, improving noise resilience in trapped ion systems.

Findings

Gate is robust to amplitude deviations in driving field

Analytical spectrum engineering of the Hamiltonian

Enhanced resilience to practical noise sources

Abstract

Entangling gates are an essential component of quantum computers. However, generating high-fidelity gates, in a scalable manner, remains a major challenge in all quantum information processing platforms. Accordingly, improving the fidelity and robustness of these gates has been a research focus in recent years. In trapped ions quantum computers, entangling gates are performed by driving the normal modes of motion of the ion chain, generating a spin-dependent force. Even though there has been significant progress in increasing the robustness and modularity of these gates, they are still sensitive to noise in the intensity of the driving field. Here we supplement the conventional spin-dependent displacement with spin-dependent squeezing, which enables a gate that is robust to deviations in the amplitude of the driving field. We solve the general Hamiltonian and engineer its spectrum analytically. We also endow our gate with other, more conventional, robustness properties, making it resilient to many practical sources of noise and inaccuracies.