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Full-Text Articles in Condensed Matter Physics
Superconducting Antenna Concept For Gravitational Waves, Armen Gulian, J Foreman, Vahan Nikoghosyan, Shmuel Nussinov, Louis Sica, Jeff Tollaksen
Superconducting Antenna Concept For Gravitational Waves, Armen Gulian, J Foreman, Vahan Nikoghosyan, Shmuel Nussinov, Louis Sica, Jeff Tollaksen
Mathematics, Physics, and Computer Science Faculty Articles and Research
The most advanced contemporary efforts and concepts for registering gravitational waves are focused on measuring tiny deviations in large arm (kilometers in case of LIGO and thousands of kilometers in case of LISA) interferometers via photons. In this report we discuss a concept for the detection of gravitational waves using an antenna comprised of superconducting electrons (Cooper pairs) moving in an ionic lattice. The major challenge in this approach is that the tidal action of the gravitational waves is extremely weak compared with electromagnetic forces. Any motion caused by gravitational waves, which violates charge neutrality, will be impeded by Coulomb …
Engineering Room-Temperature Superconductors Via Ab-Initio Calculations, Mamikon Gulian, Gurgen Melkonyan, Armen Gulian
Engineering Room-Temperature Superconductors Via Ab-Initio Calculations, Mamikon Gulian, Gurgen Melkonyan, Armen Gulian
Mathematics, Physics, and Computer Science Faculty Articles and Research
The BCS, or bosonic model of superconductivity, as Little and Ginzburg have first argued, can bring in superconductivity at room temperatures in the case of high-enough frequency of bosonic mode. It was further elucidated by Kirzhnits et al., that the condition for existence of high-temperature superconductivity is closely related to negative values of the real part of the dielectric function at finite values of the reciprocal lattice vectors. In view of these findings, the task is to calculate the dielectric function for real materials. Then the poles of this function will indicate the existence of bosonic excitations which can …
Current-Biased Transition-Edge Sensors Based On Re-Entrant Superconductors, Armen Gulian, Vahan Nikoghosyan, Jeff Tollaksen, V. Vardanyan, A. Kuzanyan
Current-Biased Transition-Edge Sensors Based On Re-Entrant Superconductors, Armen Gulian, Vahan Nikoghosyan, Jeff Tollaksen, V. Vardanyan, A. Kuzanyan
Mathematics, Physics, and Computer Science Faculty Articles and Research
Transition-edge sensors are widely recognized as one of the most sensitive tools for the photon and particles detection in many areas, from astrophysics to quantum computing. Their application became practical after understanding that rather than being biased in a constant current mode, they should be biased in a constant voltage mode. Despite the methods of voltage biasing of these sensors are well developed since then, generally the current biasing is more convenient for superconducting circuits. Thus transition-edge sensors designed inherently to operate in the current-biased mode are desirable. We developed a design for such detectors based on re-entrant superconductivity. In …
Prospective Solid-State Photonic Cryocooler Based On The “Phonon-Deficit Effect”, Gurgen Melkonyan, Armen Gulian
Prospective Solid-State Photonic Cryocooler Based On The “Phonon-Deficit Effect”, Gurgen Melkonyan, Armen Gulian
Mathematics, Physics, and Computer Science Faculty Articles and Research
In this design microwave photons are propagating in a sapphire rod, and are being absorbed by a superconductor deposited on the surface of the rod. The frequency of the radiation is tuned to be less than the energy gap in the superconductor, so that the pair breaking is not taking place. This photon pumping redistributes the electron-hole quasiparticles: their distribution function is non-equilibrium, and the “phonon-deficit effect” takes place. There is a dielectric material deposited on top of superconductor, which serves asthe “cold finger” of the cooler. Its “acoustical density” is supposed to be smaller than that of the superconducting …