Entanglement generation in superconducting qubits using holonomic operations

TL;DR

This paper demonstrates a non-adiabatic holonomic operation to entangle two fixed-frequency superconducting qubits using microwave tones, achieving high-fidelity entanglement rapidly, which advances quantum gate implementation.

Contribution

It introduces a novel holonomic entangling scheme for fixed-frequency superconducting qubits using microwave-driven cyclic evolution.

Findings

Achieved 95% fidelity in 213 ns entanglement.

Implemented a holonomic operation within a 3-level $\\Lambda$-system.

Potential for direct SWAP-type gate in microwave-controlled hardware.

Abstract

We investigate a non-adiabatic holonomic operation that enables us to entangle two fixed-frequency superconducting transmon qubits attached to a common bus resonator. Two coherent microwave tones are applied simultaneously to the two qubits and drive transitions between the first excited resonator state and the second excited state of each qubit. The cyclic evolution within this effective 3-level $\Lambda$-system gives rise to a holonomic operation entangling the two qubits. Two-qubit states with 95\% fidelity, limited mainly by charge-noise of the current device, are created within $213~\rm{ns}$. This scheme is a step toward implementing a SWAP-type gate directly in an all-microwave controlled hardware platform. By extending the available set of two-qubit operations in the fixed-frequency qubit architecture, the proposed scheme may find applications in near-term quantum applications using variational algorithms to efficiently create problem-specific trial states.