Characterising a solid state qubit via environmental noise

TL;DR

This paper introduces a method to characterize solid-state qubits by analyzing environmental noise, demonstrating that noise levels in a classical bias field reveal the qubit's energy structure.

Contribution

It presents a novel approach to determine a solid-state qubit’s energy levels through environmental noise monitoring, applicable to persistent-current qubits.

Findings

Noise in the bias field correlates with the qubit's energy level structure

The method is sensitive to changes in the applied bias field

Applicable to persistent-current qubits in lossy reservoirs

Abstract

We propose a method for characterising the energy level structure of a solid-state qubit by monitoring the noise level in its environment. We consider a model persistent-current qubit in a lossy resevoir and demonstrate that the noise in a classical bias field is a sensitive function of the applied field.