Josephson vortex interaction mediated by cavity modes: Tunable coupling for superconducting qubits

TL;DR

This paper presents a quantum-mechanical model where Josephson vortices interact via cavity modes, enabling tunable coupling for superconducting qubits, with potential applications in quantum entanglement.

Contribution

It introduces a novel quantum model for vortex interactions mediated by cavity modes, demonstrating tunable coupling for vortex-based qubits.

Findings

Interaction depends on fluxon velocities in classical regime

Vortex coupling can be tuned for entanglement in quantum regime

Different transmission line types proposed for mediating interactions

Abstract

A quantum-mechanical model for the interaction of Josephson vortices (fluxons) embedded in superconducting transmission line is presented. The vortices interact through emission and absorption of linear waves (electromagnetic cavity modes). We show that in a classical regime this peculiar type of interaction is determined by the product of instantaneous velocities of fluxons. In a quantum regime, this property provides tunable coupling between vortices which can be used for entanglement of vortex qubits. The physical mechanism of the vortex interaction is similar to that proposed for qubits based on trapped ions. Different types of transmission lines mediating the vortex interaction are proposed.