Single Shot i-Toffoli Gate in Dispersively Coupled Superconducting Qubits

TL;DR

This paper proposes a single-shot method to implement an i-Toffoli gate in superconducting qubits, significantly reducing complexity and potentially improving quantum algorithm performance.

Contribution

The authors introduce a novel single-step approach for executing multi-qubit gates in superconducting qubits, achieving high fidelity and fast operation.

Findings

Process fidelity over 98% demonstrated

Gate time of 500 ns achieved

Method extendable to more control qubits

Abstract

Quantum algorithms often benefit from the ability to execute multi-qubit (>2) gates. To date such multi-qubit gates are typically decomposed into single- and two-qubit gates, particularly in superconducting qubit architectures. The ability to perform multi-qubit operations in a single step could vastly improve the fidelity and execution time of many algorithms. Here, we propose a single shot method for executing an i-Toffoli gate, a three-qubit gate gate with two control and one target qubit, using currently existing superconducting hardware. We show numerical evidence for a process fidelity over 98% and a gate time of 500 ns for superconducting qubits interacting via tunable couplers. Our method can straight forwardly be extended to implement gates with more than two control qubits at similar fidelities.