Quantum metrology in the presence of correlated noise via Markovian embedding

Abstract

We analyze quantum metrological protocols, where the sensing system is linearly coupled to a bosonic environment, by performing a Markovian embedding of the problem based on pseudomode formalism. This allows us to effectively model the problem using low-dimensional environment and apply recently developed powerful tools that yield optimal metrological protocols and fundamental metrological bounds for correlated-noise models. We illustrate the method by investigating a frequency estimation protocol in the presence of noise modeled effectively as a damped Jaynes-Cummings dynamics.