Higher harmonic resistance oscillations in micro-bridge superconducting Nb ring

Abstract

We studied resistance oscillations in two types of superconducting mesoscopic Nb rings. In a simple superconducting ring device, a resistance oscillation with a period of the quantized magnetic flux h/2e was clearly observed. On the other hand, in a micro-bridge ring device where two-narrow parts are embedded in parallel and work as superconductor-normal metal-superconductor junctions, higher harmonic resistance oscillations were obtained when the measurement current was well-tuned. We argue that such higher harmonic resistance oscillations can be detected even in the micro-bridge Nb superconducting ring device where the device size is much larger than the coherence length of Nb.

Little-Parks oscillation and ${\bf d}$-vector texture in spin-triplet superconducting rings with bias current

“…1 (d), has been observed [5,6], validating the present approach, although its detailed structure depends on ring asymmetries [6]. In Nb rings, the j c oscillation has been observed as the LP oscillation in the resistivity [11], and for a specific ring shape, vortex penetrations seem to affect j c [7].…”

Observation of the crossover from quantum fluxoid to half-quantum fluxoid in a chiral superconducting device

“…In order to evaluate the phase of LP oscillations, a precise magnetic field measurement 0.01 mT is also required. For this purpose, we used an electromagnet with a Hall sensor to obtain the precise value of magnetic field and measured a Nb typical spin singlet 𝑠-wave superconductor ring device 28 simultaneously which was set on the same sample holder as shown in Fig. 1d.…”