Stabilization of the in-phase fluxon state by geometrical confinement in small Bi2Sr2CaCu2O8+x mesa structures
2009 (English)In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 80, no 2, 020502(R)- p.Article in journal (Refereed) Published
Thein-phase (rectangular) fluxon lattice is required for achieving coherent THzemission from stacked Josephson junctions. Unfortunately, it is usually unstabledue to mutual repulsion of fluxons in neighbor junctions, whichfavors the out-of-phase (triangular) lattice. Here we experimentally study magneticfield modulation of the critical current in small Bi-2212 mesastructures with different sizes. Clear Fraunhofer-like modulation is observed whenthe field is aligned parallel to CuO planes. For longmesas the periodicity of modulation is equal to half theflux quantum per intrinsic Josephson junction, corresponding to the triangularfluxon lattice. However, the periodicity is changed to one fluxquantum, characteristic for the rectangular fluxon lattice, both by decreasingthe length of the mesas and by increasing magnetic field.Thus, we demonstrate that the stationary in-phase fluxon state canbe effectively stabilized by geometrical confinement in small Bi-2212 mesastructures.
Place, publisher, year, edition, pages
2009. Vol. 80, no 2, 020502(R)- p.
bismuth compounds, calcium compounds, critical currents, flux-line lattice, high-temperature superconductors, Josephson effect, strontium compounds, terahertz waves
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-32819DOI: 10.1103/PhysRevB.80.020502ISI: 000268617500014OAI: oai:DiVA.org:su-32819DiVA: diva2:281638