Periodic negative magnetoresistance in granular YBa2Cu3O7−δ nanowires
1 Department of Physics, Institute of Superconductivity and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University - Ramat-Gan 52900, Israel
2 Department of Physics, Technion - Israel Institute of Technology - Haifa 32000, Israel
Received: 24 January 2013
Accepted: 26 February 2013
Magneto-transport measurements in YBa2Cu3O7−δ nanowires, comprising a single layer of a small number of grains, reveal periodic magnetoresistance oscillations in a wide temperature range below the transition. The rich structure of these oscillations manifests a negative magnetoresistance in the initial part of each cycle beginning at zero magnetic field. The salient features of these unique oscillations indicate the presence of π Josephson junctions in the granular wires, arising from the d-wave pairing symmetry in YBa2Cu3O7−δ.
PACS: 74.81.Bd – Granular, melt-textured, amorphous, and composite superconductors / 74.72.-h – Cuprate superconductors
© EPLA, 2013