Dynamics of an Ion Coupled to a Parametric Superconducting Circuit

TL;DR

This paper proposes a method to strongly couple a trapped ion's motion with a superconducting circuit by modulating magnetic flux, enabling better quantum information processing integration.

Contribution

It introduces a flux modulation technique to achieve resonant coupling between ion motion and superconducting circuits, overcoming weak natural interactions.

Findings

Resonant coupling achieved via flux modulation.

Effective time-dependent inductance generated.

Limitations compared to capacitance modulation discussed.

Abstract

Superconducting circuits and trapped ions are promising architectures for quantum information processing. However, the natural frequencies for controlling these systems -- radio frequency ion control and microwave domain superconducting qubit control -- make direct Hamiltonian interactions between them weak. In this paper we describe a technique for coupling a trapped ion's motion to the fundamental mode of a superconducting circuit, by applying to the circuit a carefully modulated external magnetic flux. In conjunction with a non-linear element (Josephson junction), this gives the circuit an effective time-dependent inductance. We then show how to tune the external flux to generate a resonant coupling between the circuit and ion's motional mode, and discuss the limitations of this approach compared to using a time-dependent capacitance.