# Coherent long-distance spin-qubit-transmon coupling

## TL;DR

This paper demonstrates a coherent long-distance coupling between spin qubits and transmon superconducting qubits on the same chip using a tunable high impedance resonator, enabling hybrid quantum architectures.

## Contribution

It introduces a novel hybrid coupling scheme with a frequency-tunable resonator that allows coherent interaction between spin and superconducting qubits at zero magnetic field.

## Key findings

- Coherent interaction observed in both resonant and dispersive regimes.
- Optimized coupling-to-decoherence ratio at a specific working point.
- Successful integration of spin and superconducting qubits on the same chip.

## Abstract

Spin qubits and superconducting qubits are among the promising candidates for a solid state quantum computer. For the implementation of a hybrid architecture which can profit from the advantages of either world, a coherent long-distance link is necessary that integrates and couples both qubit types on the same chip. We realize such a link with a frequency-tunable high impedance SQUID array resonator. The spin qubit is a resonant exchange qubit hosted in a GaAs triple quantum dot. It can be operated at zero magnetic field, allowing it to coexist with superconducting qubits on the same chip. We find a working point for the spin qubit, where the ratio between its coupling strength and decoherence rate is optimized. We observe coherent interaction between the resonant exchange qubit and a transmon qubit in both resonant and dispersive regimes, where the interaction is mediated either by real or virtual resonator photons.