Stroboscopically Robust Gates For Capacitively Coupled Singlet-Triplet Qubits

TL;DR

This paper proposes a method for designing two-qubit gates in singlet-triplet qubits that are robust against noise by using stroboscopic techniques, achieving over 99% fidelity.

Contribution

It introduces a novel approach to passive error suppression in two-qubit gates for singlet-triplet qubits through optimized stroboscopic parameters.

Findings

Achieves over 99% two-qubit gate fidelity under realistic noise conditions.

Provides a systematic way to select parameters for error-resilient gates.

Demonstrates an order of magnitude improvement over unoptimized gates.

Abstract

Recent work on Ising-coupled double-quantum-dot spin qubits in GaAs with voltage-controlled exchange interaction has shown improved two-qubit gate fidelities from the application of oscillating exchange along with a strong magnetic field gradient between adjacent dots. By examining how noise propagates in the time-evolution operator of the system, we find an optimal set of parameters that provide passive stroboscopic circumvention of errors in two-qubit gates to first order. We predict over 99% two-qubit gate fidelities in the presence of quasistatic and 1/$\textit{f}$ noise, which is an order of magnitude improvement over the typical unoptimized implementation.