Publications de Francesco Manni

Coherence and Topological Defects in Exciton-Polariton Condensates

Exciton-polaritons are hybrid quasi-particles, eigenstates of the strong coupling regime between light and matter. Their Bose-Einstein condensation has been recently demonstrated, opening the way to several fundamental investigations on the associated phen ...

EPFL2013

Spontaneous self-ordered states of vortex-antivortex pairs in a polariton condensate

Vincenzo Savona, Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis, Timothy Chi Hin Liew, Francesco Manni, Claudéric Ouellet-Plamondon

Polariton condensates have proved to be model systems to investigate topological defects, as they allow for direct and nondestructive imaging of the condensate complex order parameter. The fundamental topological excitations of such systems are quantized v ...

American Physical Society2013

Hyperbolic spin vortices and textures in exciton-polariton condensates

Benoît Marie Joseph Deveaud, Francesco Manni

From cosmology to the microscopic scales of the quantum world, the study of topological excitations is essential for the understanding of phase conformation and phase transitions. Quantum fluids are convenient systems to investigate topological entities be ...

Nature Publishing Group2013

Penrose-Onsager Criterion Validation in a One-Dimensional Polariton Condensate

Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis, Francesco Manni

We perform quantum tomography on one-dimensional polariton condensates, spontaneously occurring in linear disorder valleys in a CdTe planar microcavity sample. By the use of optical interferometric techniques, we determine the first-order coherence functio ...

Amer Physical Soc2012

Dissociation dynamics of singly charged vortices into half-quantum vortex pairs

Vincenzo Savona, Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis, Timothy Chi Hin Liew, Francesco Manni

The quest for identification and understanding of fractional vorticity is a major subject of research in the quantum fluids domain, ranging from superconductors, superfluid Helium-3 to cold atoms. In a two-dimensional Bose degenerate gas with a spin degree ...

Nature Publishing Group2012

Sleep paralysis in narcolepsy: more than just a motor dissociative phenomenon?

Francesco Manni

Sleep paralyses are viewed as pure motor phenomena featured by a dissociated state in which REM-related muscle atonia coexists with a wakefulness state of full consciousness. We present a 59-year-old man diagnosed with narcolepsy experiencing sleep paralys ...

2012

Spin-to-orbital angular momentum conversion in semiconductor microcavities

Benoît Marie Joseph Deveaud, François Morier-Genoud, Taofiq Paraïso, Konstantinos Lagoudakis, Roland Cerna, Timothy Chi Hin Liew, Francesco Manni

We experimentally demonstrate a technique for the generation of optical beams carrying orbital angular momentum using a planar semiconductor microcavity. Despite being isotropic systems with no structural gyrotropy, semiconductor microcavities, because of ...

2011

Spontaneous Pattern Formation in a Polariton Condensate

Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis, Timothy Chi Hin Liew, Francesco Manni

Exciton-polariton condensation can be regarded as a self-organization phenomenon, where phase ordering is established among particles in the system. In such condensed systems, further ordering can occur in the particle density distribution, under particula ...

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