TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.18.4.116
TI  - Photon counting statistics in Gaussian bosonic networks
PY  - 2025/04/01
UR  - https://scipost.org/SciPostPhys.18.4.116
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 18
IS  - 4
SP  - 116
A1  - Kansanen, Kalle Sulo Ukko
AU  - Portugal, Pedro
AU  - Flindt, Christian
AU  - Samuelsson, Peter
AB  - The statistics of transmitted photons in microwave cavities play a foundational role in microwave quantum optics and its technological applications. By utilizing quantum mechanical phase-space methods, we here develop a general theory of the photon counting statistics in Gaussian bosonic networks consisting of driven cavities with beamsplitter interactions and two-mode-squeezing. The dynamics of the network can be captured by a Lyapunov equation for the covariance matrix of the cavity fields, which generalizes to a Riccati equation, when counting fields are included. By solving the Riccati equation, we obtain the statistics of emitted and absorbed photons as well as the time-dependent correlations encoded in waiting time distributions and second-order coherence functions. To illustrate our theoretical framework, we first apply it to a simple linear network consisting of two coupled cavities, for which we evaluate the photon cross-correlations and discuss connections between the photon emission statistics and the entanglement between the cavities. We then consider a bosonic circulator consisting of three coupled cavities, for which we investigate how a synthetic flux may affect the direction of the photon flow, similarly to recent experiments. Our general framework paves the way for systematic investigations of the photon counting statistics in Gaussian bosonic networks.
ER  -

@Article{10.21468/SciPostPhys.18.4.116,
	title={{Photon counting statistics in Gaussian bosonic networks}},
	author={Kalle Sulo Ukko Kansanen and Pedro Portugal and Christian Flindt and Peter Samuelsson},
	journal={SciPost Phys.},
	volume={18},
	pages={116},
	year={2025},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.18.4.116},
	url={https://scipost.org/10.21468/SciPostPhys.18.4.116},
}