Simone De Liberato

Quantum Vacuum Radiation Spectra from a Semiconductor Microcavity with a Time-Modulated Vacuum Rabi Frequency

We develop a general theory of the quantum vacuum radiation generated by an arbitrary time modulation of the vacuum Rabi frequency of an intersubband transition in a doped quantum well system embedded in a planar microcavity. Both nonradiative and radiative losses are included within an input-output quantum Langevin framework. The intensity and the spectral signatures of the extra-cavity emission are characterized versus the modulation properties. For realistic parameters, the photon pair emission is predicted to largely exceed the blackbody radiation in the mid and far infrared. For strong and resonant modulation a parametric oscillation regime is achievable.

Signatures of the ultrastrong light-matter coupling regime

Aji A. Anappara, Simone De Liberato, 3 Alessandro Tredicucci, ∗ Cristiano Ciuti, Giorgio Biasiol, Lucia Sorba, and Fabio Beltram NEST CNR-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy) Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot Paris 7 and CNRS, UMR 7162, Bâtiment Condorcet, 75013 Paris (France) Laboratoire Pierre Aigrain, Ecole Normale Supérieure and CNRS, UMR 8551, 75005 Paris (France) Laboratorio Nazionale TASC CNR-INFM, Area Science Park, SS 14 Km 163.5, Basovizza, I-34012 Trieste (Italy) (Dated: March 10, 2009)

Light-Matter Decoupling in the Deep Strong Coupling Regime: The Breakdown of the Purcell Effect

Improvements in both the photonic confinement and the emitter design have led to a steady increase in the strength of the light-matter coupling in cavity quantum electrodynamics experiments. This has allowed us to access interaction-dominated regimes in which the state of the system can only be described in terms of mixed light-matter excitations. Here we show that, when the coupling between light and matter becomes strong enough, this picture breaks down, and light and matter degrees of freedom totally decouple. A striking consequence of such a counterintuitive phenomenon is that the Purcell effect is reversed and the spontaneous emission rate, usually thought to increase with the light-matter coupling strength, plummets instead for large enough couplings.

Stimulated scattering and lasing of intersubband cavity polaritons.

We present a microscopic theory describing the stimulated scattering of intersubband polariton excitations in a microcavity-embedded two-dimensional electron gas. In particular, we consider the polariton scattering induced by the interaction with longitudinal optical phonons. Our theory demonstrates the possibility of final-state stimulation for the scattering of such composite excitations, accounting for the deviations from ideal bosonicity occurring at high excitation densities. By using GaAs parameters, we predict a quantum degenerate regime and lasing without electronic population inversion in an optical pumping configuration.

Ultrastrong coupling between a cavity resonator and the cyclotron transition of a two-dimensional electron gas in the case of an integer filling factor

We investigate theoretically the coupling between a cavity resonator and the cyclotron transition of a two-dimensional electron gas under an applied perpendicular magnetic field. We derive and diagonalize an effective quantum Hamiltonian describing the magnetopolariton excitations of the two-dimensional electron gas for the case of integer filling factors. The limits of validity of the present approach are critically discussed. The dimensionless vacuum Rabi frequency

Terahertz lasing from intersubband polariton-polariton scattering in asymmetric quantum wells

{\ensuremath{\Omega}}_{0}/{\ensuremath{\omega}}_{0}

Quantum noise in photothermal cooling

(i.e., normalized to the cyclotron frequency

Excitonic spectral features in strongly coupled organic polaritons

{\ensuremath{\omega}}_{0}

Quantum model of microcavity intersubband electroluminescent devices

) is shown to scale as

Strong and Coherent Coupling between Localized and Propagating Phonon Polaritons.

\sqrt{\ensuremath{\alpha}{n}_{\text{QW}}\ensuremath{\nu}}