Characterization of coherent impurity effects in solid state qubits

TL;DR

This paper investigates how bistable coherent impurities affect solid state qubits, introducing a model to analyze their impact on qubit coherence and identifying key dynamical signatures.

Contribution

It presents a novel impurity model using a tunable spin-boson environment and analyzes the resulting qubit dynamics, highlighting non-Gaussian effects and measurement perspectives.

Findings

Identification of the dominant asymptotic rate

Signatures of non-Gaussian behavior at intermediate times

Impurity effects can be characterized via a spin-boson model

Abstract

We propose a characterisation of the effects of bistable coherent impurities in solid state qubits. We introduce an effective impurity description in terms of a tunable spin-boson environment and solve the dynamics for the qubit coherences. The dominant rate characterizing the asymptotic time limit is identified and signatures of non-Gaussian behavior of the quantum impurity at intermediate times are pointed out. An alternative perspective considering the qubit as a measurement device for the spin-boson impurity is proposed.