ABSTRACT
We describe a technique that permits broad-band, field-dependent ferromagnetic and electron paramagnetic resonance absorption measurements that is applicable to thin films and patterned micro-/nanostructured arrays and is based on a wire-wound meanderline approach. Techniques to prepare meanderlines and perform microwave measurements are described along with some demonstrations involving an electron paramagnetic resonance calibration/test material, 2,2-diphenyl-1-picryl-hydrazyl, and a ferromagnetic cobalt thin film.
ABSTRACT
A large, reentrant, Josephson current is observed in SINIS (Nb/Al/AlOx/Al/AlOx/Al/Nb) junctions at a finite voltage close to Delta/e (where Delta is the superconducting energy gap in S) and a bias current exceeding the zero-voltage Josephson current. The effect is studied using a multiterminal device configuration. A theoretical interpretation in terms of quantized electron states in the N layer is provided.
ABSTRACT
We have observed a striking anisotropy in the electrical transport of layered multiterminal SINIS structures [where S, I, and N denote a superconductor (Nb), an insulator (AlOx), and a normal metal (Al), respectively]. We find that the lateral conductivity of the N layer is dissipative, but a superconducting current can flow normal to the structure, suggesting a direct Josephson coupling between the external S electrodes. A small coherent contribution to the lateral conductivity of the N layer is observed near zero voltage.
