CNRS Materials and Quantum Phenomena Laboratory

Paris, France

CNRS Materials and Quantum Phenomena Laboratory

Paris, France
SEARCH FILTERS
Time filter
Source Type

Saad S.,CNRS Materials and Quantum Phenomena Laboratory | Hassine L.,University of Carthage | Elfahem W.,Regio IT Gesellschaft Mit Beschrankter Haftung
Photonic Sensors | Year: 2014

The high efficiency hydrogen fiber Bragg grating (FBG) sensor is presented. The sensitive film was a new alliance of palladium-silver (Pd-Ag). In addition, the titanium (Ti) layer was used as the adhesive layer. The presented sensor showed the resolution of more than 60 pm/1% H2, and a fast response time of 4 s-5 s was guaranteed in the 0.1% H2-4% H2 range. Moreover, the life time of the sensor was investigated. The obtained results showed that the sensor had an enhanced life time. Furthermore, the sensor was applied in the propulsion system fuel tank model of the aerospace vehicle. The obtained results indicated that it is a prevention system against the disaster aerospace due to hydrogen leakage. © 2014 The Author(s).


Barbieri S.,CNRS Materials and Quantum Phenomena Laboratory | Gellie P.,CNRS Materials and Quantum Phenomena Laboratory | Santarelli G.,Paris Observatory | Ding L.,CNRS Materials and Quantum Phenomena Laboratory | And 5 more authors.
Nature Photonics | Year: 2010

Mode-locked femtosecond lasers have revolutionized the field of optical metrology by allowing the realization of ultra-stable phase-coherent links between the optical-frequency domain and the radiofrequency range1-4. In this work we have used the electro-optic effect in ZnTe (ref. 5) to demonstrate that the frequency and the phase of a 2.7THz quantum cascade laser6 can be actively stabilized to the nth harmonic of the 90 MHz repetition rate (frep) of a commercial, mode-locked erbium-doped fibre laser7. The beating between the stabilized quantum cascade laser frequency and the harmonic of frep yield a signal-to-noise ratio of 80 dB in a bandwidth of 1 Hz. The technique is inherently broadband, that is, it is applicable to any quantum cascade laser source provided that its frequency falls within the spectral bandwidth of the femtosecond laser (∼5 THz)8,9. Furthermore, it is an ideal tool with which to control the phase of different quantum cascade lasers using light and compact fibre technology rather than superconducting bolometer mixers10,11. © 2010 Macmillan Publishers Limited. All rights reserved.


Todorov Y.,CNRS Materials and Quantum Phenomena Laboratory | Andrews A.M.,Solid State Electronics Institute TU Wien | Colombelli R.,University Paris - Sud | De Liberato S.,CNRS Materials and Quantum Phenomena Laboratory | And 5 more authors.
Physical Review Letters | Year: 2010

The regime of ultrastrong light-matter interaction has been investigated theoretically and experimentally, using zero-dimensional electromagnetic resonators coupled with an electronic transition between two confined states of a semiconductor quantum well. We have measured a splitting between the coupled modes that amounts to 48% of the energy transition, the highest ratio ever observed in a light-matter coupled system. Our analysis, based on a microscopic quantum theory, shows that the nonlinear polariton splitting, a signature of this regime, is a dynamical effect arising from the self-interaction of the collective electronic polarization with its own emitted field. © 2010 The American Physical Society.


Sangouard N.,University of Geneva | Sangouard N.,CNRS Materials and Quantum Phenomena Laboratory | Simon C.,University of Geneva | Simon C.,University of Calgary | And 4 more authors.
Reviews of Modern Physics | Year: 2011

The distribution of quantum states over long distances is limited by photon loss. Straightforward amplification as in classical telecommunications is not an option in quantum communication because of the no-cloning theorem. This problem could be overcome by implementing quantum repeater protocols, which create long-distance entanglement from shorter-distance entanglement via entanglement swapping. Such protocols require the capacity to create entanglement in a heralded fashion, to store it in quantum memories, and to swap it. One attractive general strategy for realizing quantum repeaters is based on the use of atomic ensembles as quantum memories, in combination with linear optical techniques and photon counting to perform all required operations. Here the theoretical and experimental status quo of this very active field are reviewed. The potentials of different approaches are compared quantitatively, with a focus on the most immediate goal of outperforming the direct transmission of photons. © 2011 American Physical Society.


Depondt P.,University Pierre and Marie Curie | Levy J.-C.S.,CNRS Materials and Quantum Phenomena Laboratory
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2011

Vortex precession was simulated in two-dimensional magnetic dots. The Landau-Lifshitz equation with exchange and dipolar interactions was integrated at a low temperature with initial conditions consisting in a single vortex situated aside from the central position. This vortex precesses around the center of the sample and either can be expelled or converges towards the center. These relaxation processes are systematically studied. A simple qualitative explanation of the observed behaviors is proposed, including seemingly somewhat erratic ones. Intrinsic pinning of the vortex motion, unconnected with defects, is also observed and an explanation thereof provided. © 2011 Elsevier B.V. All rights reserved.


Bringuier E.,CNRS Materials and Quantum Phenomena Laboratory | Bringuier E.,University Pierre and Marie Curie
Philosophical Magazine | Year: 2011

In a liquid suspension, thermophoresis is the motion of a suspended particle under a temperature gradient. In a liquid binary mixture, thermodiffusion is the generation of a composition gradient upon application of a temperature gradient. A quantitative connection is established between the two phenomena without making assumptions about their mechanisms. It is shown that Galilean invariance and the choice of a Galilean reference frame play a key role in that connection. The results are not restricted to very dilute suspensions or mixtures. © 2011 Taylor & Francis.


Depondt P.,University Pierre and Marie Curie | Levy J.-C.S.,CNRS Materials and Quantum Phenomena Laboratory
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2012

Vortex gyrotropic motion was simulated in two-dimensional square magnetic dots of three-dimensional spin vectors of nanometric size. The Landau-Lifshitz equation with exchange and dipolar interactions was integrated at different temperatures with initial conditions consisting in a single vortex shifted aside from the central position. The gyrotropic frequency is computed. The experimental observation that this frequency decreases as temperature is increased is confirmed: we suggest that the reason is the thermal dependence of the damping coefficient in Thiele's equation. Pinning of the vortex-core motion by the underlying lattice is also observed. © 2012 Elsevier B.V.


Ilisca E.,CNRS Materials and Quantum Phenomena Laboratory
EPL | Year: 2013

Non-magnetic insulating catalysts are shown to be able to convert non-equilibrium mixtures of hydrogen by an electric mechanism. The molecular electrons feel the difference of temperature between the nuclei and the thermal bath, through their "Fermi" contact interaction, and consequently transfer the rotational angular momenta to the catalyst. This transfer, realized by the electrostatic interactions between the molecular and surface ionic electron clouds, is measured by non-diagonal exchange integrals. Our simple model of single-electron excitations interprets the experimental conversion rates recently observed on different surfaces (MOF or ASW) with different technics (infrared or ionization spectroscopy) and allows the study of the conversion rates in different contexts: thermal as well as transient, metallic or oxygen-induced, ion-molecule and molecule-molecule electron exchanges. © Copyright EPLA, 2013.


Saad S.,CNRS Materials and Quantum Phenomena Laboratory | Hassine L.,University of Carthage
Photonic Sensors | Year: 2013

Three fiber Bragg grating (FBG) sensors systems for hydrogen detection are presented using the classic Pd (palladium) coating technique (500 nm) as the hydrogen sensitive film and titanium (Ti) as the adhesive layer with the etched cladding. These systems are compared and used for disaster environment prevention in hydrogen leakage environment where higher values than the normal are presented which increase the risk of explosion. With these systems, 0.1%-4% of the hydrogen volume concentration range in the volume ratio was detected and monitored experimentally in the test room with the very sensitive and stable value which reached 60 pm/1% H2. In addition, a fast response time, about 6 s, was obtained with an advanced sensor. © 2013 The Author(s).


Todorov Y.,CNRS Materials and Quantum Phenomena Laboratory
Physical Review B - Condensed Matter and Materials Physics | Year: 2014

We provide a description of the interaction between light and a three-dimensional electron gas in the framework of the Power-Zienau-Wooly (PZW) formulation of the quantum electrodynamics. The existence of the collective plasmon and plasmon-polariton modes of the gas appears as a consequence of the general properties of the PZW Hamiltonian. Our description enables a fully microscopic theory of the surface plasmon-polariton excitations, based on a quantum Hamiltonian that is free from any additional hypothesis regarding the material dispersion. This theory can therefore be applied to study the quantum optical properties of plasmon and surface plasmon waves. © 2014 American Physical Society.

Loading CNRS Materials and Quantum Phenomena Laboratory collaborators
Loading CNRS Materials and Quantum Phenomena Laboratory collaborators