Three individual two-axis control of singlet-triplet qubits in a micromagnet integrated quantum dot array

TL;DR

This paper demonstrates individual two-axis control of singlet-triplet qubits in a GaAs quantum dot array with integrated micro-magnet, advancing multi-qubit manipulation and understanding noise effects.

Contribution

It introduces coherent control of three singlet-triplet qubits in a multi-dot array with detailed noise characterization and micro-magnet analysis.

Findings

Successful coherent manipulation of three qubits

Quantitative measurement of field gradients and noise

Discussion of micro-magnet design and multi-qubit strategies

Abstract

We report individual confinement and two-axis qubit operations of two electron spin qubits in GaAs gate-defined sextuple quantum dot array with integrated micro-magnet. As a first step toward multiple qubit operations, we demonstrate coherent manipulations of three singlet-triplet qubits showing underdamped Larmor and Ramsey oscillations in all double dot sites. We provide an accurate measure of site site-dependent field gradients and rms electric and magnetic noise, and we discuss the adequacy of simple rectangular micro-magnet for practical use in multiple quantum dot arrays. We also discuss current limitations and possible strategies for realizing simultaneous multi multi-qubit operations in extended linear arrays.