Polaritons in an electron gas—quasiparticles and landau effective interactions

Authors
Bastarrachea-Magnani, MA 
Thomsen, J 
Camacho-Guardian, Arturo  ORCID logo  https://orcid.org/0000-0001-5161-5468
Bruun, GM 

Change log
Abstract

jats:pTwo-dimensional semiconductors inside optical microcavities have emerged as a versatile platform to explore new hybrid light–matter quantum states. A strong light–matter coupling leads to the formation of exciton-polaritons, which in turn interact with the surrounding electron gas to form quasiparticles called polaron-polaritons. Here, we develop a general microscopic framework to calculate the properties of these quasiparticles, such as their energy and the interactions between them. From this, we give microscopic expressions for the parameters entering a Landau theory for the polaron-polaritons, which offers a simple yet powerful way to describe such interacting light–matter many-body systems. As an example of the application of our framework, we then use the ladder approximation to explore the properties of the polaron-polaritons. Furthermore, we show that they can be measured in a non-demolition way via the light transmission/reflection spectrum of the system. Finally, we demonstrate that the Landau effective interaction mediated by electron-hole excitations is attractive leading to red shifts of the polaron-polaritons. Our work provides a systematic framework to study exciton-polaritons in electronically doped two-dimensional materials such as novel van der Waals heterostructures.</jats:p>

Publication Date
2021-10-16
Online Publication Date
2021-10-16
Acceptance Date
2021-10-13
Keywords
5108 Quantum Physics, 51 Physical Sciences
Journal Title
Atoms
Journal ISSN
2218-2004
2218-2004
Volume Title
9
Publisher
MDPI AG
Sponsorship
Danish National Research Foundation (DNRF156)
Independent Research Fund Denmark-Natural Sciences (DFF-8021-00233B)