Influence of charge fluctuations on Josephson phase-slip qubits*

The Josephson phase-slip qubit (JPSQ) [1] is a superconducting circuit designed to emulate a quantum S=1/2, with a vector dipole moment that is nearly independent of applied effective field, even near zero. This property should enable the realization of full quantum vector spin interactions, including non-Stoquastic interactions that are of interest for quantum annealing and Hamiltonian quantum computing. We characterize the influence of charge fluctuations on the JPSQ, examining both discrete quasiparticle tunneling as well as drifts and jumps in the background charge offset. In addition, we describe methods for mitigating the influence of these effects to enhance operational robustness.

[1] A. J. Kerman, New J. Phys. 21, 073030 (2019)