Concept

Quantum vortex

Publications associées (190)

Observation of Half Quantum Vortices in an Exciton-Polariton Condensate

Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis

Singly quantized vortices have already been observed in many systems, including the superfluid helium, Bose-Einstein condensates of dilute atomic gases, and condensates of exciton-polaritons in the solid state. Two-dimensional superfluids carrying spin are ...

2009

Superfluidity of polaritons in semiconductor microcavities

Romuald Houdré, Cristiano Ciuti

Superfluidity, the ability of a quantum fluid to flow without friction, is one of the most spectacular phenomena occurring in degenerate gases of interacting bosons. Since its first discovery in liquid helium-4 (refs 1, 2), superfluidity has been observed ...

Nature Publishing Group2009

Stochastic classical field model for polariton condensates

Vincenzo Savona

We use the truncated Wigner approximation to derive stochastic classical field equations for the description of polariton condensates. Our equations are shown to reduce to the Boltzmann equation in the limit of low polariton density. Monte Carlo simulation ...

2009

Efficient video coding in H.264/AVC by using audio-visual information

Touradj Ebrahimi, Jong Seok Lee

This paper proposes an efficient video coding method which utilizes audio-visual information, based on the observation that sound-emitting regions in a video sequence attract observer’s attention. The regions responsible for the sound are identified by an ...

2009

Quantized Vortices in an Exciton-Polariton Condensate

Benoît Marie Joseph Deveaud, Konstantinos Lagoudakis

One of the most striking quantum effects in an interacting Bose gas at low temperature is superfluidity. First observed in liquid 4He, this phenomenon has been intensively studied in a variety of systems for its remarkable features such as the persistence ...

Nature Publishing Group2008

Second-order time correlations within a polariton Bose-Einstein condensate in a CdTe microcavity

Benoît Marie Joseph Deveaud

Second-order time correlations of polaritons have been measured across the condensation threshold in a CdTe microcavity. The onset of Bose-Einstein condensation is marked by the disappearance of photon bunching, demonstrating the transition from a thermal- ...

American Physical Society2008

Glassy and liquid vortex matter dynamics in faulted martensites

Gérard Gremaud

We consider dislocations as vortices in elastic strain field and show that an ordered system of partial dislocations in faulted martensites is analogous to a system of flux lines (supercurrent vortices) in type-II superconductors. The network of interactin ...

2008

Two-dimensional quantum antiferromagnet with a fourfold degenerate dimer ground state

Frédéric Mila

We study the competition between antiferromagnetic order and valence-bond-crystal formation in a two-dimensional frustrated spin-1/2 model. The J(1)-J(2) model on the square lattice is further frustrated by introducing products of three-spin projectors whi ...

2008

Phase Separation and Flux Quantization in the Doped Quantum Dimer Model on Square and Triangular Lattices

Frédéric Mila

The doped two-dimensional quantum dimer model is investigated by numerical techniques on the square and triangular lattices, with significantly different results. On the square lattice, at small enough doping, there is always a phase separation between an ...

2007

Magnetic excitations near the quantum phase transition in the Ising ferromagnet LiHoF4

Henrik Moodysson Rønnow, Conradin Kraemer

Effective-medium theory and inelastic neutron scattering are used to study the magnetic excitations in the Ising ferromagnet LiHoF4 near its magnetic-field-induced quantum phase transition (QPT). As expected, the dominant mode softens at the QPT, but reach ...

AMERICAN PHYSICAL SOC2007

Graph Chatbot

Chattez avec Graph Search

Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.

AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.

Connectez-vous pour utiliser Chat avec Graph Search