Semifluxon

In superconductivity, a Semifluxon is a vortex of supercurrent carrying the magnetic flux equal to the half of the magnetic flux quantum. Semifluxons exist in the so-called 0-π long Josephson junctions at the boundary between 0 and π regions.

For the first time semifluxons were observed using d-wave superconductors at so called tricrystal grain boundaries and later in YBa₂Cu₃O₇–Nb ramp zigzags. In these systems the phase shift of π takes place inside the d-wave superconductor and not at the barrier. Due to the advent of controlled coupling by proper chosen ferromagnetic thicknesses, 0–π JJs have also recently been realized in low-T_c SFS-like systems [http:dx.doi.org\10.1103/PhysRevLett.94.197003] and underdamped SIFS-type Josephson junction [1].

References

• J. H. Xu, J. H. Miller, Jr., and C. S. Ting (1994). "π-vortex state in a long 0-π Josephson junction". Phys. Rev. B. 51: 11958. doi:10.1103/PhysRevB.51.11958.{{cite journal}}: CS1 maint: multiple names: authors list (link)

• E. Goldobin, D. Koelle, R. Kleiner (2002). "Semifluxons in long Josephson 0-π-junctions". Phys. Rev. B. 66: 100508. doi:10.1103/PhysRevB.66.100508.{{cite journal}}: CS1 maint: multiple names: authors list (link)

• C. C. Tsuei and J. R. Kirtley (2002). "d-Wave pairing symmetry in cuprate superconductors --- fundamental implications and potential applications". Physica C. 367: 1.

• H. Hilgenkamp, Ariando, H.-J. H. Smilde, D. H. A. Blank, G. Rijnders, H. Rogalla, J. R. Kirtley and C. C. Tsuei, (2003). "Ordering and manipulation of the magnetic moments in large-scale superconducting π-loop arrays". Nature (London). 442: 50.{{cite journal}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)

• M. L. Della Rocca, M. Aprili, T. Kontos, A. Gomez and P. Spatkis, (2005). "Ferromagnetic 0-π Junctions as Classical Spins". Phys. Rev. Lett. 94: 197003.{{cite journal}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)