Marcia Portella Oberli

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Second-order time correlation measurements with a temporal resolution better than 3 ps were performed on a CdTe microcavity where spontaneous Bose-Einstein condensation is observed. After the laser pulse, the nonresonantly excited thermal polariton populat ...

We present the results of a study of the dynamics of trions and excitons in a CdTe modulationdoped quantum well as a function of temperature in the low-density regime. Using three-pulse four-wave mixing technique, we show that, at low temperature, these quasi-particles are inhomo-geneously broadened and localized due to disorder effects. At higher temperatures, trions and excitons are mobile and their homogeneous broadening is largely increased as a result of acoustic phonon scattering. Consistently, time-r

We show a double path mechanism for the formation of charged excitons (trions); they are formed through bi- and trimolecular processes. This directly implies that both negatively and positively charged excitons coexist in a quantum well, even in the absenc ...

The Bogoliubov transformation of a polariton quantum fluid has recently been revealed in the four-wave mixing response of a driven microcavity polariton gas. In this work, we investigate the modifications that the dual nature of microcavity polaritons prod ...

The intramol. energy relaxation processes of UV-excited C60 mols. embedded in Ar crystals were studied by picosecond fluorescence studies and femtosecond pump-probe absorption spectroscopy. The various internal energy relaxation steps are clearly identified. The importance of intramol. energy relaxation processes in solid C60 films is underlined. [on SciFinder (R)]

Excitons and trions in a CdTe modulation-doped quantum well are investigated by picosecond three-pulse four-wave mixing experiments as a function of temperature in the low-density regime. We show that trions are mobile for high enough temperatures. The diffusivity of trions and excitons increases with temperature but, like their mobilities, is limited by acoustic-phonon scattering. Consistently, studying the decay of the interband coherence reveals an increase of the homogeneous broadening as the temperatur

The interaction between coherent polaritons and incoherent excitons plays an important role in polariton physics. Using resonant pump-probe spectroscopy with selective excitation of single polariton branches, we investigate the different dephasing mechanis ...

We report the first observation of stochastic resonance in confined exciton polaritons. We evidence this phenomena by tracking the polaritons behavior through two stochastic resonance quantifiers namely the spectral magnification factor and the signal-to-n ...

We investigate the nonlinear optical dynamics of excitons and trions in CdTe modulation-doped quantum wells by time and spectrally resolved pump-probe experiments. We find that the nonlinearities induced by excitons are different from those due to the presence of the trions. From a comparison between the exciton and trion behaviours, we show that, at low temperature, trions are formed from excitons in about 10 picoseconds and, as the temperature is increased, a thermal equilibrium is reached between exciton

We report on the effect of decoherence on polariton bistability. The polariton hysteresis loop is shown to collapse in a similar way when increasing the temperature or under nonresonant excitation power. The hysteresis upward threshold is pulled to lower e ...

The dynamics of excitons and trions in CdTe modulation-doped quantum wells are studied as a function of temperature by three-pulse four-wave mixing experiments. It is shown that trions are localized by interface roughness scattering and/or by the remote ionized donor potential at low temperature in the low-density regime. The diffusivity of excitons and trions increases with temperature but their mobilities are limited by acoustical phonon scattering, The coherence study reveals that the system is inhomogen

A Feshbach resonance occurs when the energy of two interacting free particles comes into resonance with a molecular bound state. When approaching this resonance, marked changes in the interaction strength between the particles can arise. Feshbach resonance ...

Marcia Portella Oberli

Chat with Graph Search

Temporally resolved second-order photon correlations of exciton-polariton Bose-Einstein condensate formation

Trions and excitons in CdTe quantum wells: Lifetimes, coherence, diffusion and localization

Dynamics of trion formation in GaAs quantum wells

Four-wave mixing excitations in a dissipative polariton quantum fluid

Picosecond and femtosecond studies of the energy redistribution in matrix-isolated C60 molecules

Diffusion, localization, and dephasing of trions and excitons in CdTe quantum wells

Coherent and incoherent aspects of polariton dynamics in semiconductor microcavities

Stochastic Resonance in Collective Exciton-Polariton Excitations inside a GaAs Microcavity

Nonlinear optical dynamics of excitons and trions

Reservoir-induced decoherence of resonantly excited confined polaritons

Dynamics of excitons and trions in CdTe quantum wells: Direct observation of diffusion and localization

Polaritonic Feshbach resonance

Collisional Relaxation And Oscillation Damping In A Trapped Polariton Gas

Coherent Dynamics Of Microcavity Polaritons Probed By Heterodyne Four-Wave-Mixing Spectroscopy

Time Evolution Of The Wave Function Of 0D Polaritons In The Momentum Space