Coherent control of a triangular exchange-only spin qubit

TL;DR

This paper demonstrates coherent control of a three-electron exchange-only spin qubit in a triangular quantum dot array, achieving high-fidelity single-qubit gates and highlighting the device's scalability for quantum computing.

Contribution

The study introduces a triangular quantum dot geometry for exchange-only spin qubits, enabling efficient control and high-fidelity operations with potential for scalable quantum architectures.

Findings

Achieved single-qubit gate fidelity of 99.84%.

Confirmed stable confinement of one electron per quantum dot.

Demonstrated time-domain control of exchange coupling.

Abstract

We demonstrate coherent control of a three-electron exchange-only spin qubit with the quantum dots arranged in a close-packed triangular geometry. The device is tuned to confine one electron in each quantum dot, as evidenced by pairwise charge stability diagrams. Time-domain control of the exchange coupling is demonstrated and qubit performance is characterized using blind randomized benchmarking, with an average single-qubit gate fidelity F = 99.84%. The compact triangular device geometry can be readily scaled to larger two-dimensional quantum dot arrays with high connectivity.