A5084310836- Physics of Superconductivity and Magnetism
- Rare-earth and actinide compounds
- Superconductivity in MgB2 and Alloys
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Organic and Molecular Conductors Research
- Iron-based superconductors research
- Magnetism in coordination complexes
- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Solid-state spectroscopy and crystallography
- Tuberculosis Research and Epidemiology
- Magnetic Properties of Alloys
- Quasicrystal Structures and Properties
- High-pressure geophysics and materials
- Surface and Thin Film Phenomena
- Magnesium Alloys: Properties and Applications
- Molecular Junctions and Nanostructures
- Semiconductor materials and interfaces
- Nuclear physics research studies
- Magnetic and Electromagnetic Effects
- Lipid Membrane Structure and Behavior
- Quantum, superfluid, helium dynamics
- Advancements in Semiconductor Devices and Circuit Design
- Biofield Effects and Biophysics
Université de Toulouse
2009-2020
Université Toulouse III - Paul Sabatier
2005-2020
Centre National de la Recherche Scientifique
1994-2020
Institut de Pharmacologie et de Biologie Structurale
2009-2020
Laboratoire National des Champs Magnétiques Intenses
1990-2010
Institut National des Sciences Appliquées de Toulouse
1998-2007
Laboratoire de physique de la matière condensée
1998-2001
Laboratoire de Physique Théorique de la Matière Condensée
1999
Los Alamos National Laboratory
1992-1998
University of Florida
1997
Although phthiocerol dimycocerosates (DIM) are major virulence factors of Mycobacterium tuberculosis (Mtb), the causative agent human tuberculosis, little is known about their mechanism action. Localized in outer membrane mycobacterial pathogens, DIM predicted to interact with host cell membranes. Interaction eukaryotic membranes a property shared another factor Mtb, early secretory antigenic target EsxA (also as ESAT-6). This small protein, which secreted by type VII secretion system ESX-1...
We investigated the effect of alloying on upper critical field ${H}_{c2}$ for 12 $\mathrm{Mg}{\mathrm{B}}_{2}$ films, in which disorder was introduced by growth, carbon doping or He-ion irradiation, finding a significant enhancement C-alloyed and an anomalous upward curvature ${H}_{c2}(T)$. Record high values $H_{c2}{}^{\ensuremath{\perp}}(4.2)\ensuremath{\approx}35\phantom{\rule{0.3em}{0ex}}\mathrm{T}$...
The conductance of quantum-mechanical particles through two-dimensional point contacts, with and without impurities, is calculated. It shown that, even for a zero-length constriction, steplike structures occur at integer multiples 2${e}^{2}$/h as function the constriction width. These step precursors evolve rapidly into horizontal plateaux on increasing length constriction. also that effect impurities to modify shift value steps away from quantized values.
We describe an exact formalism for the calculation of zero-temperature dc conductance various constriction-type microstructures connected to a two-dimensional half plane on both sides. From our results we obtain quantized as function constriction width at integer multiples 2${e}^{2}$/h constrictions shorter than Fermi wavelength. For longer constrictions, oscillates below values. The effect impurities is destroy quantization if are within few wavelengths aperture. show that there weak...
Abstract We report results of a study the effects strong static (up to 16 T for 8 h) and pulsed 55 single‐shot 4 × 20 repeated shots) magnetic fields on Saccharomyces cerevisiae cultures in exponential phase growth. In contrast previous reports restricted only limited number cellular parameters, we have examined wide variety processes: genome‐scale gene expression, proteome profile, cell viability, morphology, growth, metabolic fermentation activity after field exposure. None these...
We present a systematic study of the influence nanoparticle used as probe in Single Particle Tracking experiments with supported lipid bilayer model system. Quantum Dots, 40 nm and 200 diameter fluorescent latex spheres, gold colloids were attached to headgroup-labeled molecules by means an antibody. The percentage particle's surface covered antibody was also varied. made choice extract diffusion coefficient from first two points mean square displacement particle after demonstrating that...
Mycobacterium tuberculosis (Mtb) synthesizes a variety of atypical lipids that are exposed at the cell surface and help bacterium infect macrophages escape elimination by cell's immune responses. In present study, we investigate mechanism action one family hydrophobic lipids, phthiocerol dimycocerosates (DIM/PDIM), major lipid virulence factors. DIM transferred from envelope Mtb to host membranes during infection. Using polarity-sensitive fluorophore C-Laurdan, visualized decrease membrane...
The superconducting resistive transition has been investigated in high-quality ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CuO}}_{x}$ single crystals with critical temperature ${T}_{c}$ (midpoint) $=3.7\ensuremath{-}9\mathrm{K}$ magnetic fields (continuous up to 28 T and pulsed 52 T) applied perpendicular parallel the $\mathrm{ab}$ plane. dependence of upper field ${H}_{c2}^{*}$ determined as at which in-plane resistivity region is 90% or more normal state down temperatures ${T/T}_{c}=0.3,$...
Exchange bias, HE, and coercivity, HC, of antiferromagnetic (AFM)/ferromagnetic bilayers can be adjusted, after deposition, at temperatures below the Néel temperature AFM by subjecting samples to large pulsed fields (in excess HPulse=550 kOe). The efficiency process depends on system direction applied field with respect unidirectional anisotropy direction. Textured (111) Fe19Ni81/Fe50Mn50 show an HE reduction a HC increase when pulse is antiparallel anisotropy, while they only exhibit in...
The effects of neutron irradiation on normal state and superconducting properties epitaxial magnesium diboride thin films are studied up to fluences 1020cm−2. All the change systematically upon irradiation. Critical temperature is suppressed and, at highest fluence, no transition observed down 1.8K. Residual resistivity progressively increases from 1to190μΩcm; c axis expands then saturates damage level. We discuss mechanism through comparison with other procedures. magnetoresistivity...
We report measurements of the resistivity \ensuremath{\rho}, Sommerfeld coefficient specific heat \ensuremath{\gamma}, and magnetization M polycrystalline ${\mathrm{YbAgCu}}_{4}$ in high magnetic fields 0\ensuremath{\le}B\ensuremath{\le}18 T [in case M(B) to 50 T]. A comparison temperature-dependent susceptibility \ensuremath{\chi}(T) as well field-dependent \ensuremath{\gamma} Kondo theory for a J=7/2 impurity shows that correctly predicts functional dependence these quantities on B, but...
In this paper we present normal state magnetoresistivity data of magnesium diboride epitaxial thin films with different levels disorder, measured at 42K in magnetic fields up to 45 Tesla. Disorder was introduced a controlled way either by means neutron irradiation or carbon doping. From quantitative analysis the curves field parallel perpendicular plane film, extract ratio scattering times p- and s-bands. We demonstrate that undoped unirradiated film has p smaller than s ones; upon...
Abstract The structure of the compound MgVOBO3 is characterized by presence ribbons where spin-1 V3+ ions are randomly located. We present X-ray, susceptibility χ(T) as a function temperature and high-field magnetization measurements m(H) (up to 45 T) on powdered samples. These give evidence that in this system, with strong disorder magnetic chains, there arbitrarily low-energy excitations which responsible for power-law dependence we observe. find behaviour reminiscent disordered spin-½...
Upper critical fields of several magnesium diboride thin films were measured up to 28 T at the Grenoble High Magnetic Field Laboratory (GHMFL) in and 60 Laboratoire National des Champs Magnétiques Pulsés (LNCMP) Toulouse.The samples prepared both by pulsed laser deposition (PLD) hybrid physical chemical vapour (HPCVD) technique; they have temperatures between 29 39 K normal state resistivities 5 250 µΩ cm; one them has been intentionally doped with carbon.The fields, µ 0 H c2 , exceptionally...
The effects of several practical properties GaAs-AlGaAs heterostructures on the accuracy a quantum-Hall resistance standard at level 1:108 are discussed. Conduction through parallel layer, metallic current contacts, homogeneity electron density, sample size, and mobility addressed. Measurements presented concerning influences size mobility. As regards mobility, slope Hall plateau, longitudinal resistance, critical have been investigated. Recommendations given geometry Feasible measurement...
The FS of (ET)8Hg4Cl12(C6H5Br)2 can be regarded as a 2D network compensated electron and hole orbits coupled by magnetic breakthrough. Simultaneous measurements the interlayer magnetoresistance torque have been performed up to 28 T. Magnetoresistance de dHvA oscillations spectra exhibit frequency combinations typical such network. Even though some observed cannot interpreted on basis neither conventional SdH nor quantum interference, temperature field (both orientation magnitude) dependence...