The prospect of computational hardware with quantum advantage relies critically on the quality of quantum gate operations. Imperfect two-qubit gates is a major bottleneck for achieving scalable quantum information processors. Here, we propose a generalizable and extensible scheme for a two-qubit coupler switch that controls the qubit-qubit coupling by modulating the coupler frequency. Two-qubit gate operations can be implemented by operating the coupler in the dispersive regime, which is non-invasive to the qubit states. We investigate the performance of the scheme by simulating a universal two-qubit gate on a superconducting quantum circuit, and find that errors from known parasitic effects are strongly suppressed. The scheme is compatible with existing high-coherence hardware, thereby promising a higher gate fidelity with current technologies.
@article{arxiv.1803.09813,
title = {A tunable coupling scheme for implementing high-fidelity two-qubit gates},
author = {Fei Yan and Philip Krantz and Youngkyu Sung and Morten Kjaergaard and Dan Campbell and Joel I. J. Wang and Terry P. Orlando and Simon Gustavsson and William D. Oliver},
journal= {arXiv preprint arXiv:1803.09813},
year = {2018}
}