Surface impedance of real superconducting surfaces

Conductivity anisotropy and pseudogap in the microwave response of high-Tcsuperconductors

“…If the field penetration depth is much less than the surface roughness, both components of the effective (i.e., measured) surface impedance will increase in comparison with their values for a flat surface by the same factor equal to the ratio of the real and flat surface areas. If the roughness sizes are comparable to the penetration depth, a situation may occur where the microwave magnetic field H o is slightly distorted by the roughness, whereas the high-frequency current j o caused by the field decays noticeably [62]. In this case, the effective reactance ($ om 0 H 2 o dV) will exceed the sample surface resistance ($ j à o E o dV).…”

“…Whereas the R res value in classical superconductors is clearly defined as a level of the plateau in the RT curve for T`T c a4, no such plateau appears in HTSC crystals, so that by R res is meant the RT 0 value obtained by extrapolating the linear section of the RT curve for T 5 T c to zero temperature. It was experimentally established for classical superconductors that the quantity R res G o 2 and is determined by various defects in the surface layer of the sample [62,76]; based on this fact, it is usually agreed that the smaller R res , the higher the sample quality. In HTSC materials, the residual resistance also varies quadratically with frequency, but it exceeds the R res value in conventional superconductors by a factor of several dozes even in the best crystals.…”

Spatial-Dispersion Eigenvalues for Permittivity Operator of Conductors and Superconductors in a Microwave Field

“…in the similar manner as in the problem of the wave propagation in hollow waveguides and resonators [1,4,7]. For monochromatic fields, the Maxwell equations for vectors E and B in a homogeneous medium with the spatial dispersion may be written [1][2][3], taking into account the first (1) and second (cf.…”

“…Assembling the semiconductor quantum nanostructures, such as the resonant-tunneling diodes, into the microwave housing with metal resonators or microstrip lines, optimized due to the low-scale (micro and nano) dimensionality for applications in the sub-THz and THz ranges, also increases an interest to spatial effects in the simulation and modeling of micro-and nanoelectronic devices. For an explanation of the microwave spatial effects, a microscopic kinetics theory is used to obtain the constitutive equation that relates a current density and a field in a metal, and is developed on a rigorous base of the linearized Boltzmann equation [2][3][4][5][6]. The kinetics, i.e., non-equilibrium approach leads to the electrodynamic problem with a dissipation that implies the problem with a non-self-conjugated differential operator [7].…”

Transverse Plasma Resonans Mode in an Nonmagnetized Plasma and Its Practical Applications

“…(2.2) and (2.3) the value n determines the charge density. After introducing the designation [5,6] In this case the value L k presents the specific kinetic inductance of plasmo-like medium. Its existence connected with the fact that charge, having a mass, possesses inertia properties.…”