Articolo in rivista, 2014, ENG, 10.1016/j.physc.2014.06.015

YBa2Cu3O7-delta nanorings to probe fluxoid quantization in High Critical Temperature Superconductors

Arpaia, R.; Charpentier, S.; Toskovic, R.; Bauch, T.; Lombardi, F.

Chalmers University of Technology; Univ Naples Federico II, CNR, SPIN, Dipartimento Sci Fis, I-80126 Naples, Italy; Delft University of Technology

We have realized YBa2Cu3O7-delta (YBCO) nanorings and measured the magnetoresistance R(B) close to the superconducting transition. The large oscillations that we have measured can be interpreted in terms of vortex dynamics triggering the nanowires to the resistive state. The Fast Fourier Transform spectrum of the magnetoresistance oscillations shows a single sharp peak for nanorings with narrower loop arm width: this peak can be univocally associated to a h/2e periodicity as predicted for optimally doped YBCO. Moreover it is a clear evidence of a uniform vorticity of the order parameter inside the rings, confirming a high degree of homogeneity of our nanostructures. This result gives a boost to further investigations of YBCO nanorings at different dopings within the superconducting dome, where in the underdoped regime a R(B) periodicity different from the conventional h/2e has been predicted. (C) 2014 Elsevier B.V. All rights reserved.

Physica. C, Superconductivity (Print) 506 , pp. 184–187

Keywords

High-temperature superconductors, Nanorings, Fluxoid quantization, Vortex dynamics

CNR authors

Arpaia Riccardo

CNR institutes

SPIN – Istituto superconduttori, materiali innovativi e dispositivi