Improving the gate fidelity of capacitively coupled spin qubits

TL;DR

This paper introduces improved control protocols for capacitively coupled spin qubits that significantly reduce errors from charge noise and hyperfine interactions, advancing the path toward scalable quantum computing.

Contribution

It presents simple modifications to existing control sequences that enhance two-qubit gate fidelity in semiconductor spin qubits, addressing key noise sources.

Findings

Enhanced two-qubit gate fidelity demonstrated

Protocols are easy to implement in current experiments

Progress towards scalable quantum computation with spin qubits

Abstract

Capacitively coupled semiconductor spin qubits hold promise as the building blocks of a scalable quantum computing architecture with long-range coupling between distant qubits. However, the two-qubit gate fidelities achieved in experiments to date have been severely limited by decoherence originating from charge noise and hyperfine interactions with nuclear spins, and are currently unacceptably low for any conceivable multi-qubit gate operations. Here, we present control protocols that implement two-qubit entangling gates while substantially suppressing errors due to both types of noise. These protocols are obtained by making simple modifications to control sequences already used in the laboratory and should thus be easy enough for immediate experimental realization. Together with existing control protocols for robust single-qubit gates, our results constitute an important step toward scalable quantum computation using spin qubits in semiconductor platforms.