Two-Qubit Gates for Resonant Exchange Qubits

TL;DR

This paper introduces a straightforward method to perform two-qubit CPHASE gates between resonant exchange qubits using a single exchange pulse, leveraging energy conservation to suppress leakage, simplifying quantum gate operations.

Contribution

It demonstrates a simple, efficient protocol for two-qubit gates in resonant exchange qubits, contrasting with more complex existing methods that require multiple pulses.

Findings

Two-qubit CPHASE gate achieved with a single exchange pulse.

Energy conservation suppresses leakage in resonant exchange qubits.

Simplifies two-qubit gate implementation in quantum dot systems.

Abstract

A new approach to single-qubit operations using exchange interactions of single electrons in gate-defined quantum dots has recently been demonstrated: the resonant exchange qubit. We show that two-qubit operations, specifically the CPHASE gate, can be performed between resonant exchange qubits very straightforwardly, using a single exchange pulse. This is in marked contrast to the best known protocols for exchange qubits where such a gate requires many pulses so that leakage processes arising from the exchange interaction can be overcome. For resonant exchange qubits a simple two-qubit gate is possible because in this mode of operation energy conservation suppresses leakage.