Feedback control of persistent-current oscillation based on the atomic-clock technique

TL;DR

This paper introduces a feedback control scheme using atomic-clock techniques to stabilize persistent-current oscillations in flux qubits, enhancing coherence for quantum computing.

Contribution

It presents a novel hybrid structure that maps flux qubit oscillations onto an atomic transition for stabilization, a new approach in superconducting quantum circuits.

Findings

Effective suppression of flux qubit fluctuations demonstrated in simulations

Method extends potential for long-term coherence in superconducting circuits

Applicable to various superconducting quantum devices

Abstract

We propose a scheme of stabilizing the persistent-current Rabi oscillation based on the flux qubit-resonator-atom hybrid structure. The LC resonator weakly interacts with the flux qubit and maps the persistent-current Rabi oscillation onto the intraresonator electric field. This field is further coupled to a Rydberg-Rydberg transition of the $^{87}$Rb atom. The Rabi-frequency fluctuation of the flux qubit is deduced from measuring the atomic population and stabilized via feedback controlling the external flux bias. Our numerical simulation indicates that the feedback-control method can efficiently suppress the background fluctuations in the flux qubit, especially in the low-frequency limit. This technique may be extensively applicable to different types of superconducting circuits, paving a new way to long-term-coherence superconducting quantum information processing.