We propose a method to realize microwave-activated CZ gates between two remote spin qubits in quantum dots using a charge-sensitive superconducting coupler. The qubits are longitudinally coupled to the coupler, so that the transition frequency of the coupler depends on the logical qubit states; a capacitive network model using first-quantized charge operators is developed to illustrate this. Driving the coupler transition then implements a conditional phase shift on the qubits. Two pulsing schemes are investigated: a rapid, off-resonant pulse with constant amplitude, and a pulse with envelope engineering that incorporates dynamical decoupling to mitigate charge noise. We develop non-Markovian time-domain simulations to accurately model gate performance in the presence of 1/fβ charge noise. Simulation results indicate that a CZ gate fidelity exceeding 90% is possible with realistic parameters and noise models.
@article{arxiv.2409.08915,
title = {Remote Entangling Gates for Spin Qubits in Quantum Dots using a Charge-Sensitive Superconducting Coupler},
author = {Harry Hanlim Kang and Ilan T. Rosen and Max Hays and Jeffrey A. Grover and William D. Oliver},
journal= {arXiv preprint arXiv:2409.08915},
year = {2025}
}