ALP Seminar: Effective models for single-photon quantum optics

24 Feb 2025
Seminars and colloquia
Time
Venue
Simpkins Lee Seminar Room
Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Speaker(s)

Dr Astghik Saharyan, University of Paris Sud

Seminar series
ALP seminar
For more information contact

Abstract

Over the past decades, quantum optics has evolved from high-quality-factor cavities in the early experiments toward
new cavity designs involving leaky modes. Effective models to describe the dynamics of an open cavity with such
leaky modes have been extensively discussed in the literature. In many of these models, the cavity leakage to the
outside is treated as a loss introduced phenomenologically. In contrast to these, during this seminar we will focus
on a different approach where the outside is treated as part of the system. We propose an atom-cavity scheme for
single-photon generation and present a first-principle derivation of a coherent cavity-reservoir coupling function to
separately characterize photons inside and outside the cavity. This approach allows us to characterize the outgoing single photon in both the time and frequency domains.

We extend this study to more realistic cavity models, namely taking into account the multilayer dielectric structure
of cavity mirrors. In particular, we show that due to the effects induced by the multilayer nature of the cavity mirror,
even in the standardly defined high-finesse cavity regime, the cavity-reservoir system description might differ from the one where the structure of the mirror is neglected. Based on this, we define a generalized cavity response function and a cavity-reservoir coupling function, which account for the longitudinal geometric structure of the cavity mirror. This allows us to define an effective reflectivity for the cavity with a multilayer mirror as if it were sitting in a well-defined effective mirror plane. We estimate the error of such a definition by considering cavities of different lengths and mirror structures. Finally, we apply this model to characterize the dynamics of a single photon produced in such a cavity and propagating outside.

 

Astghik Saharyan1∗, Juan-Rafael Álvarez 2,  Axel Kuhn 3, and Stéphane Guérin 4
(1)Laboratoire Matériaux et Phénomènes Quantiques,
Université Paris Cité, CNRS UMR 7162, 75013, Paris, France
(2)Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
(3)University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
(4)Laboratoire Interdisciplinaire Carnot de Bourgogne, CNRS UMR 6303,
Université de Bourgogne, BP 47870, 21078 Dijon, France