Error correction for gate operations in systems of exchange-coupled singlet-triplet qubits in double quantum dots

TL;DR

This paper introduces a pulse sequence correction scheme for exchange-coupled singlet-triplet qubits in double quantum dots, significantly reducing gate errors caused by crosstalk and noise, especially under large magnetic field differences.

Contribution

The authors develop and demonstrate a new pulse sequence method that corrects for crosstalk and noise errors in singlet-triplet qubits, improving gate fidelity.

Findings

Corrected gates show several orders of magnitude reduction in infidelity.

Leakage is suppressed with large magnetic field differences.

Parameters for 24 Clifford gates are provided.

Abstract

We present a scheme for correcting for crosstalk- and noise-induced errors in exchange-coupled singlet-triplet semiconductor double quantum dot qubits. While exchange coupling allows the coupling strength to be controlled independently of the intraqubit exchange couplings, there is also the problem of leakage, which must be addressed. We show that, if a large magnetic field difference is present between the two qubits, leakage is suppressed. We then develop pulse sequences that correct for crosstalk- and noise-induced errors and present parameters describing them for the 24 Clifford gates. We determine the infidelity for both the uncorrected and corrected gates as a function of the error-inducing terms and show that our corrected pulse sequences reduce the error by several orders of magnitude.