Ref HAL: hal-03588847_v1
DOI: 10.3390/photonics9020104
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Surface plasmon resonance sensors (SPR) using copper for sensitive parts are a competitivealternative to gold and silver. Copper oxide is a semiconductor and has a non-toxic nature. Theunavoidable presence of copper oxide may be of interest as it is non-toxic, but it modifies thecondition of resonance and the performance of the sensor. Therefore, the characterization of theoptical properties of copper and copper oxide thin films is of interest. We propose a method torecover both the thicknesses and optical properties of copper and copper oxide from absorbancecurves over the(0.9; 3.5)eV range, and we use these results to numerically investigate the surfaceplasmon resonance of copper/copper oxide thin films. Samples of initial copper thicknesses 10, 30and 50 nm, after nine successive oxidations, are systematically studied to simulate the signal of aSurface Plasmon Resonance setup. The results obtained from the resolution of the inverse problem ofabsorbance are used to discuss the performance of a copper-oxide sensor and, therefore, to evaluatethe optimal thicknesses.

Ref HAL: hal-03590631_v1
DOI: 10.1016/j.molliq.2022.118575
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Le transport ultra-efficace de l'eau et des ions à l'échelle nanométrique est étudié par des simulations de dynamique moléculaire. Les nanotubes de carbone (CNTs) sont utilisés ici comme dispositifs nanofluidiques en raison de leur structure interne lisse et du compromis d'une composition très simple pour une énorme variété de propriétés. Le transport d'ions solvatés se déplaçant à l'intérieur du nanotube de carbone sous l'application d'une différence de potentiel externe a permis de mesurer le courant ionique établi à travers la zone interne du tube. Pour être le plus exhaustif possible, trois modèles d'eau populaires ont été testés pour étudier le transport ionique à l'intérieur de ce nanocanal artificiel. Les paramètres géométriques clés de la structure en carbone ont également été variés révélant une dépendance particulière de la conductance ionique à chaque paramètre étudié en accord avec le modèle théorique présenté dans cet article. Fichier révisé Version propre-Pour la mise en page Cliquez ici pour voir les références liées

Ref HAL: hal-03546784_v1
Ref Arxiv: 2111.00523v2
DOI: 10.1103/physrevb.105.024306
Ref. & Cit.: NASA ADS
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The low frequency lattice vibrations and relaxations are investigated in single crystals of the four 3D hybrid organolead perovskites, MAPbBr3, FAPbBr3, MAPbI3, and α-FAPbI3, at the Brillouin zone center using Raman and Brillouin scattering and at the zone boundary using inelastic neutron scattering. The temperature dependence of the PbX6 lattice modes in the four compounds can be renormalized into universal curves, highlighting a common vibrational dynamics at the cubic to tetragonal transition. In particular, no soft vibration is observed excluding a displacive-like transitional dynamics. The reorientational (pseudospin) motions of the molecular cations exhibit a seemingly order-disorder character recalling that of plastic crystals, but attributed to a secondary order-parameter. At ultra-low frequency, a quasi-elastic component evidenced by Brillouin scattering and associated to the unresolved central peak observed in neutron scattering, is attributed to center of mass anharmonic motions and rattling of the molecular cations in the perovskite cavities. Its partially unexpressed critical behavior at the transition points toward the general importance of defects in HOPs preventing the net divergence of order parameter correlations at the critical temperatures.

Ref HAL: hal-03562709_v1
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Résumé:

The low frequency lattice vibrations and relaxations are investigated in single crystals of the four 3Dhybrid organolead perovskites, MAPbBr3, FAPbBr3, MAPbI3, and FAPbI3, at the Brillouin zone centerusing Raman and Brillouin scattering and at the zone boundary using inelastic neutron scattering. Thetemperature dependence of the PbX6 lattice modes in the four compounds can be renormalized intouniversal curves and no soft vibration is observed excluding a displacive-like transitional dynamics. Thereorientational (pseudospin) motions of the molecular cations exhibit a seemingly order-disordercharacter recalling that of plastic crystals, but attributed to a secondary order-parameter. At ultra-lowfrequency, a quasi-elastic component evidenced by Brillouin scattering and associated to the unresolvedcentral peak observed in neutron scattering, is attributed to center of mass anharmonic motions andrattling of the molecular cations in the perovskite cavities.

Ref HAL: hal-03574108_v1
Ref Arxiv: 2202.06919
Ref INSPIRE: 2032066
DOI: 10.1140/epjc/s10052-022-10606-4
WoS: WOS:000834632900001
Ref. & Cit.: NASA ADS
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In the Minimal Supersymmetric Standard Model (MSSM) the mass of the lightest neutral Higgs boson is determined by the supersymmetric parameters. In the $m_h$MSSM the precisely measured Higgs boson replaces the trilinear coupling $A_t$ as input parameter. Expressions are derived to extract $A_t$ in a semi-analytical form as a function of the light Higgs boson (pole) mass. An algorithm is developed and implemented at two--loop precision, generalizable to higher orders, to perform this inversion consistently. The result of the algorithm, implemented in the SuSpect spectrum calculator, is illustrated on a parameter set compatible with LHC measurements.

Ref HAL: hal-03540610_v1
DOI: 10.1063/5.0080352
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Ref HAL: hal-03521600_v2
Ref Arxiv: 2201.04348
DOI: 10.1103/PhysRevApplied.18.044029
WoS: WOS:000871068700003
Ref. & Cit.: NASA ADS
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We experimentally demonstrate the difference between a ridge polariton laser and a conventional edge-emitting ridge laser operating under electron-hole population inversion. The horizontal laser cavities are 20-60µm long GaN etched ridge structures with vertical Bragg refectors. We investigatethe laser threshold under optical pumping and assess quantitatively the effect of a varying optically-pumped length. The laser effect is achieved for an exciton reservoir length of just 15% of the cavity length, which would not be possible in a conventional ridge laser, with an inversionlesspolaritonic gain about 10 times larger than in equivalent GaN lasers. This combination of a very short injection section and a strong gain paves the way to compact microlasers with nonlinear functionalities for integrated photonics.