Publications de Barbara Pietka

Selective photoexcitation of confined exciton-polariton vortices

Benoît Marie Joseph Deveaud, Gaël Nardin, François Morier-Genoud, Konstantinos Lagoudakis, Barbara Pietka

We resonantly excite exciton-polariton states confined in cylindrical traps. Using a homodyne detection setup, we are able to image the phase and amplitude of the confined polariton states. We evidence the excitation of vortex states, carrying an integer a ...

2010

Coherent Oscillations in an Exciton-Polariton Josephson Junction

Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis, Barbara Pietka

We report on the observation of spontaneous coherent oscillations in a microcavity polariton bosonic Josephson junction. Condensation of exciton polaritons here takes place under incoherent excitation in a double potential well naturally formed in the diso ...

American Physical Society2010

Probability density tomography of microcavity polaritons confined in cylindrical traps of various sizes

Benoît Marie Joseph Deveaud, Gaël Nardin, François Morier-Genoud, Barbara Pietka, Taofiq Paraïso, Ounsi El Daïf, Roland Cerna

We present the optical tomography of the probability density of microcavity polaritons, confined in three dimensions by cylindrical traps of various sizes. Collecting the photoluminescence emitted by the quasimodes under continuous nonresonant laser excita ...

Elsevier2010

Dynamics of Long-Range Ordering in an Exciton-Polariton Condensate

Benoît Marie Joseph Deveaud, Gaël Nardin, Konstantinos Lagoudakis, Barbara Pietka

We report on time-resolved measurements of the first order spatial coherence in an exciton-polariton Bose-Einstein condensate. Long-range spatial coherence is found to set in right at the onset of stimulated scattering, on a picosecond time scale. The cohe ...

American Physical Society2009

Coherent optical control of the wave function of zero dimensional exciton polaritons

Benoît Marie Joseph Deveaud, Vincenzo Savona, Gaël Nardin, François Morier-Genoud, Marcia Portella Oberli, Barbara Pietka, Taofiq Paraïso, Davide Sarchi, Ounsi El Daïf, Roland Cerna

Control of the wave function of confined microcavity polaritons is demonstrated experimentally and theoretically by means of tailored resonant optical excitation. Three dimensional confinement is achieved by etching mesas on top of the microcavity spacer l ...

2009

Coexisting nonequilibrium condensates with long-range spatial coherence in semiconductor microcavities

Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis, Barbara Pietka

Real- and momentum-space spectrally resolved images of microcavity polariton emission in the regime of condensation are investigated under nonresonant excitation using a laser source with reduced intensity fluctuations on the time scale of the exciton life ...

2009

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