arXiv subjects

A. T. Findikoglu

Publications and source records attributed to A. T. Findikoglu.

2 recordsLinked to original sources

arXiv2006

Classical Propagation of Light in Spatio-Temporal Periodic Media

We analyze the propagation of electromagnetic waves in media where the dielectric constants undergo rapid temporal periodic modulation. Both spatially homogeneous and periodic media are studied. Fast periodic temporal modulation of the dielectric constant of a homogeneous medium leads to existence of photonic band-gap like phenomena. In the presence of both spatial and tem- poral periodicity the electromagnetic spectrum is described in a four-dimensional cube, defining an effective Brillouin zone. In the case of incommensurability between space and time periodicities, completely dispersed point spectra exist.

physics.optics↗

arXiv2003

Microwave performance of high-density bulk MgB2

We have performed microwave measurements on superconducting hot-isostatically- pressed (HIPed) bulk MgB2 using a parallel-plate resonator technique. The high density and strength of the HIPed material allowed preparation of samples with mirror-like surfaces for microwave measurements. The microwave surface resistance decreased by about 40% at 20 K when the root-mean-square surface roughness was reduced from 220 nm to 110 nm through surface-polishing and ion-milling. The surface resistance was independent of surface microwave magnetic field at least up to 4 Oe and below 30 K. We attribute this behavior, and the overall low surface resistance (~0.8 mOhms at 10 GHz and 20 K), to the high density of our samples and the absence of weak links between grains.

cond-mat.supr-con↗