Diabatic gates for frequency-tunable superconducting qubits

TL;DR

This paper demonstrates fast, high-fidelity diabatic two-qubit gates in frequency-tunable superconducting qubits by synchronizing entangling parameters with leakage minima, enabling robust and efficient quantum operations.

Contribution

It introduces a novel diabatic gate technique that achieves low error rates and fast operation times in superconducting qubits, with a validated synchronization method.

Findings

Pauli error rates as low as 4.3e-3 achieved

Gate times as short as 18 ns demonstrated

Synchronization landscape matches model predictions

Abstract

We demonstrate diabatic two-qubit gates with Pauli error rates down to $4.3(2)\cdot 10^{-3}$ in as fast as 18 ns using frequency-tunable superconducting qubits. This is achieved by synchronizing the entangling parameters with minima in the leakage channel. The synchronization shows a landscape in gate parameter space that agrees with model predictions and facilitates robust tune-up. We test both iSWAP-like and CPHASE gates with cross-entropy benchmarking. The presented approach can be extended to multibody operations as well.