Correlated Dephasing Noise in Single-photon Scattering

TL;DR

This paper presents a theoretical framework for analyzing how correlated dephasing noise affects single-photon scattering in waveguide-QED systems, enabling noise characterization through spectroscopic measurements.

Contribution

It introduces a combined input-output and stochastic approach to predict photon transmission and noise effects in solid-state quantum emitters with correlated dephasing.

Findings

Homodyne detection and photon counting reveal the transmittance's modulus and phase despite noise.

Spectroscopic measurements can fully characterize noise correlations, equivalent to Ramsey interferometry.

Applicable to various noise models like Gaussian, white, telegraph, and 1/f noise.

Abstract

We develop a theoretical framework to describe the scattering of photons against a two-level quantum emitter with arbitrary correlated dephasing noise. This is particularly relevant to waveguide-QED setups with solid-state emitters, such as superconducting qubits or quantum dots, which couple to complex dephasing environments in addition to the propagating photons along the waveguide. Combining input-output theory and stochastic methods, we predict the effect of correlated dephasing in single-photon transmission experiments with weak coherent inputs. We discuss homodyne detection and photon counting of the scattered photons and show that both measurements give the modulus and phase of the single-photon transmittance despite the presence of noise and dissipation. In addition, we demonstrate that these spectroscopic measurements contain the same information as standard time-resolved Ramsey interferometry, and thus they can be used to fully characterize the noise correlations without direct access to the emitter. The method is exemplified with paradigmatic correlated dephasing models such as colored Gaussian noise, white noise, telegraph noise, and 1/f-noise, as typically encountered in solid-state environments.