Year: 2004
Type: article
Abstract: We propose, implement, and test experimentally long Josephson $0\mathrm{\text{\ensuremath{-}}}\ensuremath{\pi}$ junctions fabricated using conventional $\mathrm{N}\mathrm{b}\mathrm{\text{\ensuremath{-}}}{\mathrm{A}\mathrm{l}\mathrm{O}}_{x}\mathrm{\text{\ensuremath{-}}}\mathrm{N}\mathrm{b}$ technology. We show that by using a pair of current injectors one can create an arbitrary discontinuity of the Josephson phase and, in particular, a $\ensuremath{\pi}$ discontinuity, just as in $d$-wave/$s$-wave or in $d$-wave/$d$-wave junctions, and study fractional Josephson vortices which spontaneously appear. Moreover, using such junctions, we can investigate the dynamics of the fractional vortices---a domain which is not yet available for natural $0\mathrm{\text{\ensuremath{-}}}\ensuremath{\pi}$ junctions due to their inherently high damping. We observe half-integer zero-field steps which appear on the current-voltage characteristics due to the hopping of semifluxons.
Source: Physical Review Letters
Authors: E. Goldobin, A. Sterck, T. Gaber, D. Koelle, R. Kleiner
Institutions: Karlsruhe Institute of Technology, University of Tübingen
Language: Latvian
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2072854019