title: Ultrastrong light-matter coupling regime with polariton dots.
abstract: The regime of ultrastrong light-matter interaction has been investigated theoretically and experimentally, using zero-dimensional electromagnetic resonators coupled with an electronic transition between two confined states of a semiconductor quantum well. We have measured a splitting between the coupled modes that amounts to 48% of the energy transition, the highest ratio ever observed in a light-matter coupled system. Our analysis, based on a microscopic quantum theory, shows that the nonlinear polariton splitting, a signature of this regime, is a dynamical effect arising from the self-interaction of the collective electronic polarization with its own emitted field.
authors.affiliation: Laboratoire Matériaux et Phénomenes Quantiques, Unversité Paris Diderot-Paris 7, CNRS-UMR 7162, 75013 Paris, France. yanko.todorov@univ-paris-diderot.fr
authors.forename: Y
authors.initials: Y
authors.lastname: Todorov
authors.forename: A M
authors.initials: AM
authors.lastname: Andrews
authors.forename: R
authors.initials: R
authors.lastname: Colombelli
authors.forename: S
authors.initials: S
authors.lastname: De Liberato
authors.forename: C
authors.initials: C
authors.lastname: Ciuti
authors.forename: P
authors.initials: P
authors.lastname: Klang
authors.forename: G
authors.initials: G
authors.lastname: Strasser
authors.forename: C
authors.initials: C
authors.lastname: Sirtori