Magnetic phase shifter for superconducting qubit

TL;DR

This paper introduces a contactless magnetic phase shifter for superconducting qubits, utilizing a magnetized dot to induce controllable phase shifts in flux-based circuits, enabling new functionalities and studies of Josephson vortices.

Contribution

The authors designed and demonstrated a novel magnetic phase shifter that can generate arbitrary phase shifts without contact, enhancing control in superconducting quantum circuits.

Findings

The magnetic phase shifter effectively induces tunable phase shifts.

It can serve as an external current source in superconducting circuits.

Potential for studying fractional Josephson vortices.

Abstract

We have designed and investigated a contactless magnetic phase shifter for flux-based superconducting qubits. The phase shifter is realized by placing a perpendicularly magnetized dot at the centre of a superconducting loop. The flux generated by this magnetic dot gives rise to an additional shielding current in the loop, which, in turn, induces a phase shift. By modifying the parameters of the dot an arbitrary phase shift can be generated in the loop. This magnetic phase shifter can, therefore, be used as an external current source in superconducting circuits, as well as a suitable tool to study fractional Josephson vortices.