Properties of superconductor–Luttinger-liquid hybrid systems

In this paper, we review some recent results concerning the physics of superconductor–Luttinger-liquid proximity systems. We discuss both equilibrium (the pair amplitude, Josephson current, and the local density of states) and nonequilibrium (the subgap current) properties.     

Study of the dependence of the photoacoustic signal amplitude from methane on different collisional partners

In a previous work we observed that the photoacoustic signal from methane in air decreases to one-seventh the figure obtained in mixtures with pure nitrogen. A close resonance between oxygen's first vibrational mode (ν) and the methane bending modes may be responsible for this phenomenon. Indeed, the long relaxation time of the ν mode (1554 cm⁻¹) causes the oxygen to store energy internally instead of releasing it to heat. In this work we study different collisional partners (Helium, C₂Cl₂F₄) which may help transfer this vibrational energy to kinetic.In order to carry out the experiment we used the resonant photoacoustic technique by means of an OPO tuned at 3.3 μm, which corresponds to the methane ν₃ vibrational mode, and an aluminum acoustic resonator with rectangular cross section, Brewster windows at the resonance nodes of the second longitudinal mode at 2300 Hz and Q-factor of 165. A rate-equation-based model, which describes the time evolution of the excited populations and the heating of the sample for the case of Helium, shows good agreement with the experimental results. The addition of C₂Cl₂F₄ showed an increase of the methane PA signal up to values even higher than for methane-nitrogen mixtures.     

Synthesis and characterization of electrospun PVdF-HFP/silane-functionalized ZrO2 hybrid nanofiber electrolyte with enhanced optical and electrochemical properties

A facile method to produce a hybrid of organic-inorganic nanofiber electrolyte via electrospinning is hereby presented. The incorporation of functionalized zirconium oxide (ZrO₂) nanoparticles into poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) and complexed with lithium trifluoromethanesulfonate (LiCF₃SO₃) provided an enhanced optical transmissivity and ionic conductivity. The dependence of the nanofiber's morphology, optical and electrochemical properties on the various ZrO₂ loading was studied. Results show that while nanofiller content was increased, the diameter of the nanofibers was reduced. The improved bulk ionic conductivity of the nanofiber electrolyte was at 1.96 × 10⁻⁵ S cm⁻¹. Owing to the enhanced dispersibility of the 3-(trimethoxysilyl)propyl methacrylate (MPS) functionalized ZrO₂, the optical transmissivity of the nanofiber electrolyte was improved significantly. This new nanofiber composite electrolyte membrane with further development has the potential to be next generation electrolyte for energy efficient windows like electrochromic devices.