Browsing by Author "Askerzade, I. N."

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Open Access
Angular dependence of upper critical field in two-band Ginzburg-Landau theory
(Elsevier B.V., 2007) Askerzade, I. N.; Tanatar, Bilal
Generalization of two-band Ginzburg-Landau (GL) theory to the case of anisotropic mass is presented. The temperature dependence of the anisotropy parameter of upper critical field γc 2 (T) = Hc 2∥ (T) / Hc 2⊥ (T) and angular dependence of Hc2(θ, T) are calculated using anisotropic mass two-band Ginzburg-Landau theory of superconductors. It is shown that, with decreasing temperature anisotropy parameter γc2(T) is increased. Results of our calculations are in agreement with experimental data for single crystal MgB2. © 2007.
Open Access
Anisotropy of critical fields in MgB2: Two-Band ginzburg-landau theory for layered superconductors
(IOP Institute of Physics Publishing, 2009) Askerzade, I. N.; Tanatar, Bilal
The temperature dependence of the anisotropy parameter of upper critical field γHc2 (T) Hc2 (T)/Hc2 (T) and London penetration depth γλ(T) λ(T)/λ (T) are calculated using two-band Ginzburg-Landau theory for layered superconductors. It is shown that, with decreasing temperature the anisotropy parameter γHc2 (T) is increased, while the London penetration depth anisotropy γλ(T) reveals an opposite behavior. Results of our calculations are in agreement with experimental data for single crystal MgB2 and with other calculations. Results of an analysis of magnetic field Hc1 in a single vortex between superconducting layers are also presented.
Open Access
Effect of Superconductivity–Magnetism Interaction on the Differential Conductivity in Ho(NiB)2C/Ag Point Contacts
(M A I K Nauka - Interperiodica, 2002) Askerzade, I. N.; Tanatar, Bilal
In terms of the Blonder–Tinkham–Klapwjik theory, the differential conductivity of Ho(NiB)2C/Agpoint contacts is explained by the coexistence of magnetic ordering and superconductivity in holmium boroncarbides.
Open Access
Effect of the superconductivity transition on the response of YBCO edge transition bolometers
(2003) Bozbey, Ali; Fardmanesh, Mehdi; Askerzade, I. N.; Banzet, M.; Schubert, J.
Dependence of the phase and magnitude of the response of Y-Ba-Cu-O edge transition bolometers on the superconducting transition is studied. The responses of both large and small area devices were investigated and several anomalies are observed. The response of small area LaAlO3 devices considerably differed from that expected based on the dR/dT curve. This discrepancy is observed to be strongly dependent on the superconducting transition. Both the phase and magnitude/(dR/dT) of the response of the devices showed abrupt changes for below the Tc-onset when measured versus temperature, while the phase variation also showed strong dependence on the modulation frequency. We present the analysis and propose mechanisms responsible for the modulation frequency dependence of the response characteristics versus temperature, within the superconductivity transition region of the devices.
Open Access
Effects of anisotropy on the critical temperature in layered nonadiabatic superconductors
(Elsevier Science B.V., 2003) Askerzade, I. N.; Tanatar, Bilal
The generalized anisotropic Eliashberg theory is employed to study the critical temperature of layered nonadiabatic superconductors where the relevant phonon energy is comparable to the Fermi energy. We consider a two-dimensional model appropriate for cuprate compounds and recently discovered superconductor magnesium-diboride (MgB2) which also reveals layered structure. By using the McMillan approximation we present the result of calculations of critical temperature Tc. It is shown that the critical temperature is enhanced due to the influence of anisotropy and nonadiabaticity.
Open Access
Plasma modes in layered superconductors
(Elsevier B.V., 2005) Askerzade, I. N.; Tanatar, Bilal
An expression for the plasmon spectrum in the layered superconductors with arbitrary thickness of planes, which varies within a wide range is obtained. The obtained result can be attractive for the explanation of experimental data on plasmon modes in cuprates and other recently discovered superconductors.