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Semi-fluxons in long Josephson 0-pi-junctions

E. Goldobin·D. Koelle·R. Kleiner
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Abstract

We investigate analytically long Josephson junctions with phase pi-discontinuity points. Such junctions are usually fabricated as a ramp between a superconductor like YBCO with d-wave symmetry of the order parameter and an s-wave superconductor like Nb. From the top, they look like zigzags with pi-jumps of the Josephson phase at the corners. These pi-jumps, at certain conditions, lead to the formation of half-integer flux quanta, which we call semi-fluxons, pinned at the corners. We derive a version of sine-Gordon equation which describes the dynamics of the Josephson phase in such structures, and obtain an explicit formula which describes the shape of a semi-fluxon. Some properties of semi-fluxons are discussed. We propose a way to construct artificial pi-junctions using only s-wave superconductors.

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E. Goldobin, D. Koelle, R. Kleiner. 2002-07-31. Semi-fluxons in long Josephson 0-pi-junctions. https://doi.org/10.1103/physrevb.66.100508

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