Results for "Jerome Faist"

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Electrically controlled terahertz magneto-optical phenomena in continuous and patterned grapheneMar 07 2017The magnetic circular dichroism and the Faraday rotation are the fundamental phenomena of great practical importance arising from the breaking of the time reversal symmetry by a magnetic field. In most materials the strength and the sign of these effects ... More
Intersubband gain in a Bloch oscillator and Quantum cascade laserMay 17 2002The link between the inversion gain of quantum cascade structures and the Bloch gain in periodic superlattices is presented. The proposed theoretical model based on the density matrix formalism is able to treat the gain mechanism of the Bloch oscillator ... More
Pulses from a mid-infrared quantum cascade laser frequency comb using an external compressorMay 14 2019A Martinez-type stretcher-compressor is used to modify the spectral phases of a high-power (~1 W) QCL comb emitted at 8.2 {\mu}m with more than 100 cm-1 spectral bandwidth. Using this scheme, we demonstrate a compression of the QCL output from a 134 ps ... More
Coherent Frequency Combs produced by Self Frequency Modulation in Quantum Cascade LasersNov 28 2013One salient characteristic of Quantum Cascade Laser (QCL) is its very shor gain recovery time that so far thwarted the attempts to achieve self-mode locking of the device into a train of single pulses. We show theoretically that four wave mixing, combined ... More
High quality factor, fully switchable THz superconducting metasurfaceNov 13 2014We present a complementary THz metasurface realised with Niobium thin film which displays a quality factor Q=54 and a fully switchable behaviour as a function of the temperature. The switching behaviour and the high quality factor are due to a careful ... More
InGaAs/AlInGaAs THz Quantum Cascade Lasers operating up to 195 K in strong magnetic fieldNov 06 2014Feb 20 2015Terahertz quantum cascade lasers based on InGaAs wells and quaternary AlInGaAs barriers were measured in magnetic field. This study was carried out on a four quantum well active region design with photon energy of 14.3 meV processed both with Au and Cu ... More
Intrinsic linewidth of quantum cascade laser frequency combsJun 20 2015The frequency noise power spectral density of a free-running quantum cascade laser frequency comb is investigated. A plateau is observed at high frequencies, attributed to the quantum noise limit set by the Schawlow-Townes formula for the total laser ... More
Coexisting frequency combs spaced by an octave in a monolithic quantum cascade laserOct 24 2018Quantum cascade lasers are proving to be instrumental in the development of compact frequency comb sources at mid-infrared and terahertz frequencies. Here we demonstrate a heterogeneous terahertz quantum cascade laser with two active regions spaced exactly ... More
Mid-Infrared Single Photon CountingNov 29 2005We report a procedure to detect mid-infrared single photons at 4.65 um via a two-stage scheme based on Sum Frequency Generation, using a Periodically Poled Lithium Niobate (PPLN) nonlinear crystal and a Silicon Avalanche Photodiode. An experimental investigation ... More
Measuring intensity correlations of a THz quantum cascade laser around its threshold at sub-cycle timescalesNov 29 2016The quantum nature of photonic systems is reflected in the photon statistics of the light they emit. Therefore, the development of quantum optics tools with single photon sensitivity and excellent temporal resolution is paramount to the development of ... More
On-chip mid-infrared and THz frequency combs for spectroscopyJul 10 2019Frequency combs have revolutionized time and frequency metrology and in recent years, new frequency comb lasers that are highly compact or even on-chip have been demonstrated in the mid-infrared and THz regions of the electromagnetic spectrum. The emerging ... More
C^r surface diffeomorphisms with no maximal entropy measureMay 18 2012For any $1\leq r<\infty$, we build on the disk and therefore on any manifold, a $C^r$-diffeomorphism with no measure of maximal entropy.
Numerical Relativity CM1-a and CM1-b sessionsFeb 05 2001Feb 13 2001Numerical Relativity is concerned with solving the Einstein equations, as well as any field or matter equations on curved space-time, by means of computer calculations. The methods developed for this purpose up to now, as well as the addressed physical ... More
Pure braids, a new subgroup of the mapping class group and finite type invariantsDec 03 1997In the study of the relation between the mapping class group M of a surface and the theory of finite-type invariants of homology 3-spheres, three subgroups of the mapping class group play a large role. They are the Torelli group, the Johnson subgroup ... More
Existence and uniqueness of optimal maps on Alexandrov spacesMay 03 2007The purpose of this paper is to show that in a finite dimensional metric space with Alexandrov's curvature bounded below, Monge's transport problem for the quadratic cost admits a unique solution.
The timescale for giant planet formation : constraints from the rotational evolution of exoplanet host starsOct 17 2008The timescale over which planets may form in the circumstellar disks of young stars is one of the main issues of current planetary formation models. We present here new constraints on planet formation timescales derived from the rotational evolution of ... More
Gravity, Dimension, Equilibrium, & ThermodynamicsMar 30 2006Is it actually possible to interpret gravitation as space's property in a pure classical way. Then, we note that extended self-gravitating system equilibrium depends directly on the number of dimension of the space in which it evolves. Given those precisions, ... More
Towards a Science of MindNov 06 2018Apr 26 2019The ancient mind/body problem continues to be one of deepest mysteries of science and of the human spirit. Despite major advances in many fields, there is still no plausible link between subjective experience (qualia) and its realization in the body. ... More
Mysteries of Visual ExperienceApr 28 2016Mar 20 2018Science is a crowning glory of the human spirit and its applications remain our best hope for social progress. But there are limitations to current science and perhaps to any science. The general mind-body problem is known to be intractable and currently ... More
Behavior of the SU(2)-Reidemeister torsion form by mutationMar 21 2012Apr 01 2013In this paper, we prove that the Reidemeister torsion twisted by the adjoint representation, which is considered as a 1-form, on the SU(2)-character variety of a knot exterior is invariant under mutation along a Conway sphere.
Ice : The paradigm of wild plasticityFeb 14 2019Ice plasticity has been thoroughly studied, owing to its importance in glaciers and ice sheets dynamics. In particular, its anisotropy (easy basal slip) has been suspected for a long time, then fully characterized 40 years ago. More recently emerged the ... More
The Lagrangian filtration of the mapping class group and finite-type invariants of homology spheresAug 23 2004In a recent paper we defined a new filtration of the mapping class group--the "Lagrangian" filtration. We here determine the successive quotients of this filtration, up to finite index. As an application we show that, for any additive invariant of finite-type ... More
Inflation: Where Do We Stand?Oct 26 2004In this short review, the predictions of inflation are presented and compared to the most recent measurements of the Cosmic Microwave Background (CMB) anisotropy. It is argued that inflation is compatible with these observations but that these ones are ... More
The Theory of InflationJul 29 2018This article contains a concise review of the theory of inflation. We discuss its main theoretical aspects as well as its observational predictions. We also explain how the most recent astrophysical observations constrain the inflationary scenario.
Finite, closed-form expressions for the partition function and for Euler, Bernoulli, and Stirling numbersMar 08 2011May 24 2011We find general solutions to the generating-function equation sum c_q^{(X)} z^q = F(z)^X, where X is a complex number and F(z) is a convergent power series with |F(0)| >0. We then use these results to derive finite expressions containing only integers ... More
Maximal Entropy Measures for Piecewise Affine Surface HomeomorphismsSep 13 2007Feb 19 2009We study the dynamics of piecewise affine surface homeomorphisms from the point of view of their entropy. Under the assumption of positive topological entropy, we establish the existence of finitely many ergodic and invariant probability measures maximizing ... More
Strong coupling in the far-infrared between graphene plasmons and the surface optical phonons of silicon dioxideMay 29 2014We study plasmonic resonances in electrostatically gated graphene nanoribbons on silicon dioxide substrates. Absorption spectra are measured in the mid-far infrared and reveal multiple peaks, with width-dependent resonant frequencies. We calculate the ... More
Sur une généralisation de la notion de système dynamique de rang un définie par une propriété de pistage (On a weak version of the rank one property defined by shadowing)Sep 13 2007We investigate a shadowing property which appears naturally in the study of piecewise monotonic maps of the interval. It turns out to be a weak form of the rank one property, a well-known notion in abstract ergodic theory. We show that this new property ... More
Introduction to discrete functional analysis techniques for the numerical study of diffusion equations with irregular dataMay 11 2015Feb 24 2016We give an introduction to discrete functional analysis techniques for stationary and transient diffusion equations. We show how these techniques are used to establish the convergence of various numerical schemes without assuming non-physical regularity ... More
Action at a distance and causality in quantum theoryOct 28 2013Aug 16 2014The relation between quantum theory and special relativity is peculiar. On the one hand it is close and essential. Steven Weinberg [1], for example, takes the position that the standard model is an inevitable consequence of the marriage of the two theories. ... More
On Wave Particle DualityJul 04 2012Oct 29 2012In a recent paper a mathematical model for quantum measurement was presented. The phenomenon of wave particle duality, which is introduced in every beginning course of quantum theory, can be explained using this model. Although it is a special case of ... More
Organic Superconductors: when correlations and magnetism walk inJan 27 2012Feb 18 2012This survey provides a brief account for the start of organic superconductivity motivated by the quest for high Tc superconductors and its development since the eighties'. Besides superconductivity found in 1D organics in 1980, progresses in this field ... More
Stabilite de Faber-Krahn en courbure de Ricci positiveApr 08 2005P. Berard and D. Meyer proved a Faber-Krahn inequality for domains in compact manifolds with positive Ricci curvature. We prove stability results for this inequality.
The role of magnetic fields in governing the angular momentum evolution of solar-type starsOct 27 2008I review the development of ideas regarding the angular momentum evolution of solar-type stars, from the early 60's to the most recent years. Magnetic fields are the central agent that dictates the rotational evolution of solar-type stars, both during ... More
Nonlinear integrable systems related to arbitrary space-time dependence of the spectral transformJan 14 1994We propose a general algebraic analytic scheme for the spectral transform of solutions of nonlinear evolution equations. This allows us to give the general integrable evolution corresponding to an arbitrary time and space dependence of the spectral transform ... More
Concordance of boundary linksJun 22 2003We show that the twisted signature invariants of boundary link concordance derived from unitary representations of the free group are actually ordinary link concordance invariants. We also show how the discontinuity locus of this signature function is ... More
A marvelous contribution from Michel Henon to globular cluster's study : the isochrone clusterNov 17 2014A survey of Michel Henon contributions to the study of globular cluster systems.
Vlavov and Poisson equations in the context of self-gravitating systemsFeb 20 2004We present Vlasov's equation and its association with Poisson's equation in the context of modelling self-gravitating systems such as Globular Clusters or Galaxies. We first review the classical hypotheses of the model. We continue with a presentation ... More
Equilibrium of stellar dynamical systems in the context of the Vlasov-Poisson modelJun 14 2007This short review is devoted to the problem of the equilibrium of stellar dynamical systems in the context of the Vlasov-Poisson model. In a first part we will review some classical problems posed by the application of the Vlasov-Poisson model to the ... More
Addendum and correction to: Homology cylinders: an enlargement of the mapping class groupJul 30 2002Dec 31 2002In a previous paper [Homology cylinders: an enlargement of the mapping class group, Algebr. Geom. Topol. 1 (2001) 243--270, arXiv:math.GT/0010247], a group H_g of homology cylinders over the oriented surface of genus g is defined. A filtration of H_g ... More
On the Matrix-Element Expansion of a Circulant DeterminantFeb 20 2015Apr 21 2015The determinant of an $N \times N$ circulant matrix $M = {\rm CIRC}[x_0, x_1, ..., x_{N-1}$] can be expanded in the form det$ ~M= \sum C_{a_0 a_1 ...a_{N-1}} x_{a_0} x_{a_1}...x_{a_{N-1}}$. By using the generating function of a restricted, mod-$N$ partition ... More
The Quantum State of Inflationary PerturbationsSep 14 2012This article reviews the properties of the quantum state of inflationary perturbations. After a brief description of the inflationary background, the wavefunction of the Mukhanov-Sasaki variable is calculated and shown to be that of a strongly squeezed ... More
Everything You Always Wanted To Know About The Cosmological Constant Problem (But Were Afraid To Ask)May 15 2012This article aims at discussing the cosmological constant problem at a pedagogical but fully technical level. We review how the vacuum energy can be regularized in flat and curved space-time and how it can be understood in terms of Feynman bubble diagrams. ... More
Inflation and Precision CosmologyDec 18 2003A brief review of inflation is presented. After having demonstrated the generality of the inflationary mechanism, the emphasize is put on its simplest realization, namely the single field slow-roll inflationary scenario. Then, it is shown how, concretely, ... More
Quintessence: a mini-reviewMar 28 2008Models where the accelerated expansion of our Universe is caused by a quintessence scalar field are reviewed. In the framework of high energy physics, the physical nature of this field is discussed and its interaction with ordinary matter is studied and ... More
Inflationary Perturbations: the Cosmological Schwinger EffectApr 24 2007This pedagogical review aims at presenting the fundamental aspects of the theory of inflationary cosmological perturbations of quantum-mechanical origin. The analogy with the well-known Schwinger effect is discussed in detail and a systematic comparison ... More
Bowen factors, their degree, and codings of surface diffeomorphismsJul 11 2018We show that symbolic finite-to-one extensions of the type constructed by O. Sarig for surface diffeomorphisms induce H\"older-continuous conjugacies on large sets, sometimes preserving transitivity. We deduce this from their Bowen property. This notion, ... More
Mysteries of Visual ExperienceApr 28 2016Sep 28 2016Science is a crowning glory of the human spirit and its applications remain our best hope for social progress. But there are limitations to current science and perhaps to any science. The general mind-body problem is known to be intractable and currently ... More
Velocity-induced collapses of stable neutron starsJul 12 2001The collapse of spherical neutron stars is studied in General Relativity. The initial state is a stable neutron star to which an inward radial kinetic energy has been added through some velocity profile. For two different equations of state and two different ... More
Harnack type inequality for positive solution of some integral equationFeb 07 2013In this paper, we establish some Harnack type inequalities satisfied by positive solutions of nonlocal inhomogeneous equations arising in the description of various phenomena ranging from population dynamics to micro-magnetism. For regular domains, we ... More
On a simple criterion for the existence of a principal eigenfunction of some nonlocal operatorsJun 25 2011In this paper we are interested in the existence of a principal eigenfunction of a nonlocal operator which appears in the description of various phenomena ranging from population dynamics to micro-magnetism. More precisely, we study the following eigenvalue ... More
Generalizing Ramanujan's J FunctionsSep 27 2011Oct 03 2011We generalize Ramanujan's expansions of the fractional-power Euler functions (q^{1/5})_{\infty} = [ J_1 - q^{1/5} + q^{2/5} J_2 ](q^5)_{\infty} and (q^{1/7})_{\infty} = [ J_1 + q^{1/7} J_2 - q^{2/7} + q^{5/7} J_3 ] (q^7)_{\infty} to (q^{1/N})_{\infty}, ... More
Dynamics of Anisotropic UniversesMar 30 2006We present a general study of the dynamical properties of Anisotropic Bianchi Universes in the context of Einstein General Relativity. Integrability results using Kovalevskaya exponents are reported and connected to general knowledge about Bianchi dynamics. ... More
Syntax-based Default Reasoning as Probabilistic Model-based DiagnosisFeb 27 2013We view the syntax-based approaches to default reasoning as a model-based diagnosis problem, where each source giving a piece of information is considered as a component. It is formalized in the ATMS framework (each source corresponds to an assumption). ... More
A determinant formula for the partition function p(7k + a)Jun 14 2011Jun 16 2011We derive expressions for the partition function p(n), with n in the form 7k+a, as (k+1)-dimensional determinants.
Inflationary Cosmological Perturbations of Quantum-Mechanical OriginJun 01 2004This review article aims at presenting the theory of inflation. We first describe the background spacetime behavior during the slow-roll phase and analyze how inflation ends and the Universe reheats. Then, we present the theory of cosmological perturbations ... More
The almost Borel structure of diffeomorphisms with some hyperbolicityMar 11 2014These lecture notes focus on a recent result of Mike Hochman: an arbitrary standard Borel system can be embedded into a mixing Markov with equal entropy, respecting all invariant probability measures, with two exceptions: those carried by periodic orbits ... More
Renormalized kinetic theory of classical fluids in and out of equilibriumFeb 01 2011We present a theory for the construction of renormalized kinetic equations to describe the dynamics of classical systems of particles in or out of equilibrium. A closed, self-consistent set of evolution equations is derived for the single-particle phase-space ... More
A Factorization of the Conway PolynomialNov 08 1997A string link S can be closed in a canonical way to produce an ordinary closed link L. We also consider a twisted closing which produces a knot K. We give a formula for the Conway polynomial of L as a product of the Conway polynomial of K times a power ... More
Pincement spectral en courbure de Ricci positiveApr 08 2005We show that for n dimensional manifolds whose the Ricci curvature is greater or equal to n-1 and for k in {1,...,n+1}, the k-th eigenvalue for the Laplacian is close to n if and only if the manifold contains a subset which is Gromov-Hausdorff close to ... More
Lithium depletion and the rotational history of exoplanet host starsAug 28 2008Sep 03 2008Israelian et al. (2004) reported that exoplanet host stars are lithium depleted compared to solar-type stars without detected massive planets, a result recently confirmed by Gonzalez (2008). We investigate whether enhanced lithium depletion in exoplanet ... More
Labeled binary planar trees and quasi-Lie algebrasApr 13 2005Apr 17 2009We study the natural map eta between a group of binary planar trees whose leaves are labeled by elements of a free abelian group H and a certain group D(H) derived from the free Lie algebra over H. Both of these groups arise in several different topological ... More
Homology cylinders: an enlargement of the mapping class groupOct 26 2000Apr 24 2001We consider a homological enlargement of the mapping class group, defined by homology cylinders over a closed oriented surface (up to homology cobordism). These are important model objects in the recent Goussarov-Habiro theory of finite-type invariants ... More
A volume form on the SU(2)-representation space of knot groupsSep 27 2004Mar 06 2009For a knot K in S^3 we construct according to Casson--or more precisely taking into account Lin and Heusener's further works--a volume form on the SU(2)-representation space of the group of K. We prove that this volume form is a topological knot invariant ... More
Cosmic Inflation: Trick or Treat?Feb 14 2019Discovered almost forty years ago, inflation has become the leading paradigm for the early universe. Originally invented to avoid the fine-tuning puzzles of the standard model of cosmology, the so-called hot Big Bang phase, inflation has always been the ... More
The Observational Status of Cosmic Inflation after PlanckFeb 19 2015The observational status of inflation after the Planck 2013 and 2015 results and the BICEP2/Keck Array and Planck joint analysis is discussed. These pedagogical lecture notes are intended to serve as a technical guide filling the gap between the theoretical ... More
Cosmological perturbations and classical change of signatureSep 27 1995Cosmological perturbations on a manifold admitting signature change are studied. The background solution consists in a Friedmann-Lemaitre-Robertson- Walker (FLRW) Universe filled by a constant scalar field playing the role of a cosmological constant. ... More
Subshifts of quasi-finite typeMay 12 2003May 08 2004We introduce subshifts of quasi-finite type as a generalization of the well-known subshifts of finite type. This generalization is much less rigid and therefore contains the symbolic dynamics of many non-uniform systems, e.g., piecewise monotonic maps ... More
Finite volume schemes for diffusion equations: introduction to and review of modern methodsJul 07 2014We present Finite Volume methods for diffusion equations on generic meshes, that received important coverage in the last decade or so. After introducing the main ideas and construction principles of the methods, we review some literature results, focusing ... More
The maximal decomposition of the Turaev-Viro TQFTAug 20 2009Sep 01 2009In a previous work arXiv:0903.4512, we have built an homotopical Turaev-Viro invariant and an HQFT from the universal graduation of a spherical category. In the present paper, we show that every graduation $(G,p)$ of a spherical category $\C$ defines ... More
The invariant of Turaev-Viro from Group categoryAug 24 2006Aug 29 2006A Group category is a spherical category whose simple objects are invertible. The invariant of Turaev-Viro with this particular category is in fact the invariant of Dijkgraaf-Witten whose the group and the 3-cocycle is given by the simple objects and ... More
Cosmic Inflation, Quantum Information and the Pioneering Role of John S Bell in CosmologyMar 29 2019According to the theory of cosmic inflation, the large scale structures observed in our Universe (galaxies, clusters of galaxies, Cosmic Background Microwave - CMB - anisotropy ...) are of quantum mechanical origin. They are nothing but vacuum fluctuations, ... More
Dimensional entropies and semi-uniform hyperbolicityFeb 03 2011We describe dimensional entropies introduced in a previous work list some of their properties and give some new proofs. These entropies allowed the definition of entropy-expanding maps. We introduce a new notion of entropy-hyperbolicity for diffeomorphisms. ... More
Nonlocal refuge model with a partial controlMay 30 2013In this paper, we analyse the structure of the set of positive solutions of an heterogeneous nonlocal equation of the form: $$ \int_{\Omega} K(x, y)u(y)\,dy -\int_ {\Omega}K(y, x)u(x)\, dy + a_0u+\lambda a_1(x)u -\beta(x)u^p=0 \quad \text{in}\quad \times ... More
Singular measure as principal eigenfunction of some nonlocal operatorsFeb 05 2013Feb 06 2013In this paper, we are interested in the spectral properties of the generalised principal eigenvalue of some nonlocal operator. That is, we look for the existence of some particular solution $(\lambda,\phi)$ of a nonlocal operator. $$\int_{\O}K(x,y)\phi(y)\, ... More
Convergence to equilibrium for positive solutions of some mutation-selection modelAug 29 2013In this paper we are interested in the long time behaviour of the positive solutions of the mutation selection model with Neumann Boundary condition: $$ \frac{\partial u(x,t)}{dt}=u\left[r(x)-\int_{\O}K(x,y)|u|^{p}(y)\,dy\right]+\nabla\cdot\left(A(x)\nabla ... More
The rotational evolution of young low mass starsDec 18 2007Star-disk interaction is thought to drive the angular momentum evolution of young stars. In this review, I present the latest results obtained on the rotational properties of low mass and very low mass pre-main sequence stars. I discuss the evidence for ... More
Regularity Problem for Extremal VectorsMar 08 2007In this paper, we will use results developed by Ansari and Enflo in the theory of bounded linear operators with dense range. We define two maps, with regards to some parameters, that control surjectivity default of a given operator, and prove analycity ... More
Longest common substring for random subshifts of finite typeMay 20 2019In this paper we study the behaviour of the longest common substring for random subshifts of finite type (for dynamicists) or the longest common substring for random sequences in random environments (for probabilists). We prove that for invariant measures ... More
The large-parts formula for p(n)Feb 07 2010A new formula for the partition function $p(n)$ is developed. We show that the number of partitions of $n$ can be expressed as the sum of a simple function of the two largest parts of all partitions. Specifically, if $a_1 + >... + a_k = n$ is a partition ... More
A continuous, piecewise affine surface map with no measure of maximal entropyFeb 16 2009It is known that piecewise affine surface homeomorphisms always have measures of maximal entropy. This is easily seen to fail in the discontinuous case. Here we describe a piecewise affine, globally continuous surface map with no measure of maximal entropy. ... More
Factorization of and Determinant Expressions for the Hypersums of Powers of IntegersApr 21 2011Apr 26 2011We derive a compact determinant formula for calculating and factorizing the hypersum polynomials S^{(L)}_k(N) \equiv \sum_{n_1=1}^N ...\sum_{n_{L+1}=1}^{n_{L}}(n_{L+1})^k expressed in the variable N(N+L+1)
Inflation after Planck: and the winners areDec 13 2013We review the constraints that the recently released Cosmic Microwave Background (CMB) Planck data put on inflation and we argue that single field slow-roll inflationary scenarios (with minimal kinetic term) are favored. Then, within this class of models, ... More
Hamiltonian quantization of General Relativity with the change of signatureFeb 15 1994We show in this article how the usual hamiltonian formalism of General Relativity should be modified in order to allow the inclusion of the Euclidean classical solutions of Einstein's equations. We study the effect that the dynamical change of signature ... More
High power spatial single-mode quantum cascade lasers at 8.9 $μ$mSep 29 2006High performance of InP-based quantum cascade lasers emitting at $\lambda$ ~ 9$\mu$m are reported. Thick electroplated gold layer was deposited on top of the laser to improve heat dissipation. With one facet high reflection coated, the devices produce ... More
Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmonsJan 22 2015May 01 2015Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers ... More
Sequential resonant tunneling in quantum cascade lasersOct 01 2008A model of sequential resonant tunneling transport between two-dimensional subbands that takes into account explicitly elastic scattering is investigated. It is compared to transport measurements performed on quantum cascade lasers where resonant tunneling ... More
Positive Cross Correlations in a Normal-Conducting Fermionic Beam SplitterOct 10 2005Feb 03 2006We investigate a beam splitter experiment implemented in a normal conducting fermionic electron gas in the quantum Hall regime. The cross-correlations between the current fluctuations in the two exit leads of the three terminal device are found to be ... More
Microcanonical and resource-theoretic derivations of the thermal state of a quantum system with noncommuting chargesDec 03 2015Jul 21 2016The grand canonical ensemble lies at the core of quantum and classical statistical mechanics. A small system thermalizes to this ensemble while exchanging heat and particles with a bath. A quantum system may exchange quantities represented by operators ... More
Quantum Coarse-Graining: An Information-Theoretic Approach to ThermodynamicsJul 11 2016We investigate fundamental connections between thermodynamics and quantum information theory. First, we show that the operational framework of thermal operations is nonequivalent to the framework of Gibbs-preserving maps, and we comment on this gap. We ... More
Coupled-waveguides for dispersion compensation in semiconductor lasersNov 24 2017The generation of optical frequency combs via direct electrical pumping of semiconductor lasers is an attractive alternative to the well-established mode-locked laser sources in terms of compactness, robustness and integrability. However, the high chromatic ... More
High-Power Directional Emission from Microlasers with Chaotic ResonatorsJun 15 1998Jul 15 1998High-power and highly directional semiconductor cylinder-lasers based on an optical resonator with deformed cross section are reported. In the favorable directions of the far-field, a power increase of up to three orders of magnitude over the conventional ... More
Octave-spanning semiconductor laserJul 11 2014We present here a semiconductor injection laser operating in continuous wave with an emission covering more than one octave in frequency, and displaying homogeneous power distribution among the lasing modes. The gain medium is based on a heterogeneous ... More
Room temperature terahertz polariton emitterJan 09 2012The strong-coupling regime between an electronic transition and the photonic mode of a optical resonator manifests itself in the lifting of the degeneracy between the two modes and the creation of two polariton states with mixed optical and electronic ... More
Magneto-transport controlled by Landau polariton statesMay 02 2018Oct 17 2018Hybrid excitations, called polaritons, emerge in systems with strong light-matter coupling. Usually, they dominate the linear and nonlinear optical properties with applications in quantum optics. Here, we show the crucial role of the electronic component ... More
Computing and Testing Pareto Optimal CommitteesMar 18 2018Selecting a set of alternatives based on the preferences of agents is an important problem in committee selection and beyond. Among the various criteria put forth for the desirability of a committee, Pareto optimality is a minimal and important requirement. ... More
Hopf algebroids and secondary characteristic classesNov 20 2007Dec 04 2007We study a Hopf algebroid, $\calh$, naturally associated to the groupoid $U_n^\delta\ltimes U_n$. We show that classes in the Hopf cyclic cohomology of $\calh$ can be used to define secondary characteristic classes of trivialized flat $U_n$-bundles. For ... More
Are the two peaks of the Cathedral QPO real harmonics?Nov 07 2011We present a study of the two main peaks of the so-called cathedral QPO in XTE J1859+226. While looking at the temporal evolution of the two features we show that they do not manifest the same amplitude of variations of their power, and do not seem to ... More
Object Recognition with Imperfect Perception and Redundant DescriptionFeb 13 2013This paper deals with a scene recognition system in a robotics contex. The general problem is to match images with <I>a priori</I> descriptions. A typical mission would consist in identifying an object in an installation with a vision system situated ... More
The Galactic population of HMXBs as seen with INTEGRAL during its four first years of activityJan 07 2008We collected the parameters (position, absorption, spin, orbital period, etc..), when known, of all Galactic sources detected by INTEGRAL during its four first years of activity. We use these parameters to test theoretical predictions. For example, it ... More