Decoherence of a tunable capacitively shunted flux qubit
Abstract
Quantum annealing is a method to solve optimization problems that leverages quantum tunneling in a coupled qubit system. We present a detailed study of the coherence of a tunable capacitively-shunted flux qubit, designed for coherent quantum annealing applications. We find that for high qubit frequencies, thermal noise in the bias line makes a significant contribution to the relaxation, arising from the design choice to experimentally explore both fast annealing and high-frequency control. The measured dephasing rate is primarily due to intrinsic low-frequency flux noise in the two qubit loops, with additional contribution from the low-frequency noise of control electronics used for fast annealing. Our results characterize decoherence in a realistic setup for quantum annealing and are relevant for ongoing efforts toward building superconducting quantum annealers with increased coherence.
Keywords
Cite
@article{arxiv.2307.13961,
title = {Decoherence of a tunable capacitively shunted flux qubit},
author = {R. Trappen and X. Dai and M. A. Yurtalan and D. Melanson and D. M. Tennant and A. J. Martinez and Y. Tang and J. Gibson and J. A. Grover and S. M. Disseler and J. I. Basham and R. Das and D. K. Kim and A. J. Melville and B. M. Niedzielski and C. F. Hirjibehedin and K. Serniak and S. J. Weber and J. L. Yoder and W. D. Oliver and D. A. Lidar and A. Lupascu},
journal= {arXiv preprint arXiv:2307.13961},
year = {2025}
}
Comments
14 pages, 6 figures