arXiv subjects

Mauro M. Doria

Publications and source records attributed to Mauro M. Doria.

39 records · Page 3Linked to original sources

arXiv1997

Properties of High-Tc Single Crystals as Natural Interferometers in the THz Frequency Range

We consider oblique incidence of (p)TM-polarized wave on the anisotropic superconducting slab, immersed on a dielectric media, such that its uniaxial (c) axis is perpendicular to the surfaces. The below and above plasma frequency transmissivity patterns are studied and several of its properties determined, within the context of the Maxwell-London theory. Below, the regime is attenuated for any incident angle, and there is a transmissivity maximum, quite pronounced in case of a very high external dielectric constant. Above, a propagative regime exists where the superconductor is a natural optical resonator, and we show here that the minimum of the transmission peaks are modulated by an envelope function associated to the Brewster condition. We propose this set-up to obtain light with an extremely small transverse wavelength inside the superconductor.

cond-mat.supr-con↗

arXiv1997

Collective Oscillations in Superconducting Thin Films in the Presence of Vortices

A plasma wave propagates inside an anisotropic superconducting film sandwiched between two semi-infinite non-conducting bounding dieletric media. Along the c-axis, perpendicular to the film surfaces, an external magnetic field is applied. We show how vortices, known to cause dissipation and change the penetration depth, affect the propagative mode. We obtain the complex wave number of this mode and, using YBCO at 4 K as an example, determine a region where vortex contribution is dominant and dissipation is small.

cond-mat.supr-con↗

arXiv1997

Plasma Waves in Anisotropic Superconducting Films Below and Above the Plasma Frequency

We consider wave propagation inside an anisotropic superconducting film sandwiched between two semi-infinite non-conducting bounding dieletric media such that along the c-axis, perpendicular to the surfaces, there is a plasma frequency $ω_p$ below the superconducting gap. Propagation is assumed to be parallel to the surfaces in the dielectric medium, where amplitudes decay exponentially.Below $ω_p$, the amplitude also evanesces inside the film, and we retrieve the experimentally measured lower dispersion relation branch, $ω\propto \sqrtβ$, and the recently proposed higher frequency branch, $ω\propto 1/\sqrtβ$.Above $ω_p$, propagation is of the guided wave type, i.e., a dispersive plane wave confined inside the film that reflects into the dielectric interfaces,and the modes are approximately described by $ω\approx ω_p \sqrt{ 1+ (β/β_0)^2}$, where $β_0$ is discussed here.

cond-mat.supr-con↗