title: Ground State Electroluminescence.
abstract: Electroluminescence, the emission of light in the presence of an electric current, provides information on the allowed electronic transitions of a given system. It is commonly used to investigate the physics of strongly coupled light-matter systems, whose eigenfrequencies are split by the strong coupling with the photonic field of a cavity. Here we show that, together with the usual electroluminescence, systems in the ultrastrong light-matter coupling regime emit a uniquely quantum radiation when a flow of current is driven through them. While standard electroluminescence relies on the population of excited states followed by spontaneous emission, the process we describe herein extracts bound photons from the dressed ground state and it has peculiar features that unequivocally distinguish it from usual electroluminescence.
authors.affiliation: Interdisciplinary Theoretical Science Research Group (iTHES), RIKEN, Wako-shi, Saitama 351-0198, Japan.
authors.forename: Mauro
authors.initials: M
authors.lastname: Cirio
authors.affiliation: School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: Simone
authors.initials: S
authors.lastname: De Liberato
authors.affiliation: CEMS, RIKEN, Saitama 351-0198, Japan.
authors.forename: Neill
authors.initials: N
authors.lastname: Lambert
authors.affiliation: CEMS, RIKEN, Saitama 351-0198, Japan.|Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA.
authors.forename: Franco
authors.initials: F
authors.lastname: Nori