Publications by Barbara Pietka

Analytical method for determining quantum well exciton properties in a magnetic field

Benoît Marie Joseph Deveaud, François Morier-Genoud, Barbara Pietka

We develop an analytical approximate method for determining the Bohr radii of Wannier-Mott excitons in thin quantum wells under the influence of magnetic field perpendicular to the quantum well plane. Our hybrid variational-perturbative method allows us to ...

American Physical Society2015

Magnetic Field Induced Redistribution of Exciton-Polariton Density on Confined Modes

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

The influence of magnetic field on confined exciton-polariton modes inside a semiconductor microcavity is discussed. The three-dimensional confinement for exciton-polaritons is achieved by the mesa structures confining the photonic part of polaritons. We o ...

Polish Acad Sciences Inst Physics2012

Collisional damping of dipole oscillations in a trapped polariton gas

Benoît Marie Joseph Deveaud, François Morier-Genoud, Taofiq Paraïso, Marcia Portella Oberli, Roland Cerna, Barbara Pietka

We study the relaxation dynamics of a trapped polariton gas in the nonlinear regime. We excite the three lowest energy states of the system and observe the time evolution of the polariton density in the momentum space. At a low excitation power, the dynami ...

2011

Polariton Condensation in a One-Dimensional Disordered Potential

Vincenzo Savona, Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis, Barbara Pietka, Luca Fontanesi, Francesco Manni

We study the coherence and density modulation of a nonequilibrium exciton-polariton condensate in a one-dimensional valley with disorder. By means of interferometric measurements we evidence a modulation of the ﬁrst-order coherence function and we relate i ...

American Physical Society2011

Coherent oscillations between orbital angular momentum polariton states in an elliptic resonator

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

We optically excited the eigenmodes of an elliptic resonator in a semiconductor microcavity. Using a pulsed excitation, we created a superposition of eigenmodes, and imaged the temporal evolution of the coherent emission pattern. A semiconductor quantum we ...

2011

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

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

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

Phase-resolved imaging of confined exciton-polariton wave functions in elliptical traps

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

We study the wave functions of exciton polaritons trapped in the elliptical traps of a patterned microcavity. A homodyne detection setup with numerical off-axis filtering allows us to retrieve the amplitude and the phase of the wave functions. Doublet stat ...

2010

Selective photoexcitation of confined exciton-polariton vortices

Benoît Marie Joseph Deveaud, François Morier-Genoud, Gaël Nardin, 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

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

Probability density optical tomography of confined quasiparticles in a semiconductor microcavity

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

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

AIP American Institute of Physics2009

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

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

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

Enhancement of microcavity polariton relaxation under confinement

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

We experimentally investigate the relaxation of spatially confined microcavity polaritons. We measure the time- and energy-resolved photoluminescence under resonant excitation and in the low-density regime. In this way, we have access to the time evolution ...

2009