Detecting Casimir Forces through a Tunneling Electromechanical Transducer

We propose the use of a tunneling electromechanical transducer to dynamically detect Casimir forces between two conducting surfaces. The maximum distance for which Casimir forces should be detectable with our method is around $1 \mu$m, while the lower limit is given by the ability to approach the surfaces. This technique should permit to study gravitational forces on the same range of distances, as well as the vacuum friction provided that very low dissipation mechanical resonators are used.Comment: 10 pages, revtex, 4 figures (not included

Low- and high-density features of IR luminescence of Xe2_{2} excimers produced by electron impact

Electron--impact excitation of Xe atoms in pure Xe gas and in a Xe(10 %)--Ar(90 %) mixture has led to the discovery of infrared (IR) luminescence of Xe$_{2}$ excimers. The investigation of the emission spectrum at low gas density has allowed the identification of the molecular states involved in the transition. When the gas density is increased to values up to 40 times larger than the density of the ideal gas at standard temperature and pressure, the interaction of the excimer with the dense environment produces a strong red--shift of the spectrum that is interpreted in terms of many--body effects

Polarized thermal emission by thin metal wires

We report new measurements of the linear polarization of thermal radiation emitted by incandescent thin tungsten wires, with thicknesses ranging from five to hundred microns. Our data show very good agreement with theoretical predictions, based on Drude-type fits to measured optical properties of tungsten.Comment: 12 pages, 4 encapsulated figures. This new version matches the one published in New. J. Phys.. Improved presentation, more references added, and one new figure include

The QUAX proposal: a search of galactic axion with magnetic materials

Aim of the QUAX (QUaerere AXion) proposal is to exploit the interaction of cosmological axions with the spin of electrons in a magnetized sample. Their effect is equivalent to the application of an oscillating rf field with frequency and amplitude which are fixed by axion mass and coupling constant, respectively. The rf receiver module of the QUAX detector consists of magnetized samples with the Larmor resonance frequency tuned to the axion mass by a polarizing static magnetic field. The interaction of electrons with the axion-equivalent rf field produces oscillations in the total magnetization of the samples. To amplify such a tiny field, a pump field at the same frequency is applied in a direction orthogonal to the polarizing field. The induced oscillatory magnetization along the polarizing field is measured by a SQUID amplifier operated at its quantum noise level.Comment: 5 pages, Contribution for the proceedings of the TAUP2015, International Conference on Topics in Astroparticle and Underground Physics, 7-11 September 2015, Torino, Ital