Related papers: Infrared absorption in superconducting MgB2
MgB2 superconducting wires with critical temperature Tc approaching 40 K were used for preparation of MgB2/Ag and MgB2/In junctions. The differential conductance vs. voltage characteristics of N-S junctions exhibit clear contribution of…
We present broadband dual frequency comb laser absorption measurements of 2% H$_2$O (natural isotopic abundance of 99.7% H$_2^{16}$O) in air from 6600-7650 cm$^{-1}$ (1307-1515 nm) with a spectral point spacing of 0.0068 cm$^{-1}$.…
We studied the far-infrared reflectance of superconducting MgB2 in and out of equilibrium using pulsed synchrotron radiation. The equilibrium data can be described by a single energy gap at 2 Delta / hc = 43 cm-1. The fit improves slightly…
We use tunable laser based Angle Resolved Photoemission Spectroscopy to study the electronic structure of the multi-band superconductor, MgB2. These results form the base line for detailed studies of superconductivity in multi-band systems.…
The electrical resistivity $\rho$ and upper critical field $H_{c2}$ were measured in MgB$_2$ disordered by nuclear reactor neutrons. We found that superconducting temperature $T_c$ decreases under irradiation from 40 to 5 K. Despite strong…
We have searched for HI 21-cm absorption in 11 strong MgII systems ($W_{\rm r}$(MgII $\lambda 2796$) $\ge 1$ \AA) at $0.3<z<0.5$ using the Giant Metrewave Radio Telescope. We have detected HI 21-cm absorption in two of these. From the…
Interband absorption and luminescence of quasi-two-dimensional, circularly symmetric, N_e electron quantum dots are studied at high magnetic fields, 8<B<60 T, and low temperatures, T<<2 K. In the N_e=0 and 1 dots, the initial and final…
The equation of state for ultra-dense matter can be tested from observations of the ratio of mass to radius of neutron stars. This could be measured precisely from the redshift of a narrow line produced on the surface. X-rays bursts have…
We report on the presence of weak links in the intermetallic superconductor MgB2 from the non-resonant microwave absorption (NRMA) studies on the MgB2 thin film. The strong low field signal, which is the characteristics of weak links and…
We demonstrate that absorption saturation of a mid-infrared intersubband transition can be engineered to occur at moderate light intensities of the order of 10-20 kW$.$cm$^{-2}$ and at room temperature. The structure consists of an array of…
We have successfully prepared the MgB2 superconducting bulk and powdered materials by the method of combustion synthesis. The starting materials used in this study were powders of Mg and B. X-ray powder diffraction pattern was well assigned…
We investigate the nonlinear optical response of a commercial extended-wavelength In$_{0.81}$Ga$_{0.19}$As photodetector. Degenerate two-photon absorption in the mid-infrared range is observed at room temperature using a quantum cascade…
We present electrical transport, magnetization, and specific heat measurements on bulk MgB2 samples (T_{c} = 38.5 K) synthesized under 200 MPa pressure using a process based on hot isostatic pressing with cooling under pressure. The samples…
We study the effects of pressure on the electron-phonon interaction in MgB_2 using density-functional-based methods. Our results show that the superconductivity in MgB_2 vanishes by 100 GPa, and then reappears at higher pressures. In…
A new 3.2--3.5~$\mu$m spectrum of the protostar Mon~R2/IRS-3 confirms our previous tentative detection of a new absorption feature near 3.25 $\mu$m. The feature in our new spectrum has a central wavelength of 3.256 $\mu$m (3071 cm$^{-1}$)…
Enhanced microwave absorption, larger than that in the normal state, is observed in fine grains of type-II superconductors (MgB$_2$ and K$_3$C$_{60}$) for magnetic fields as small as a few $\%$ of the upper critical field. The effect is…
Within a recently proposed variational approach it has been shown that, in $La_{1-x}A_xMnO_3$ perovskites with $0<x<0.5$, near the metal-insulator transition, the combined effect of the magnetic and electron-phonon interactions pushes the…
The MgB2 superconductor synthesized in a flowing argon atmosphere using nanometer magnesium powder as the raw materials, denoted as Nano-MgB2, has been studied by the technique of in-situ high temperature resistance measurement (HT-RT…
We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a…
Microwave absorption measurements in magnetic fields from zero up to 16 T were used to determine the temperature range of superconducting fluctuations above the superconducting critical temperature T_c in YBa_2Cu_3O_{7-\delta}. Measurements…