Dresden 2020 – wissenschaftliches Programm
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TT 16.37: Poster
Montag, 16. März 2020, 15:00–19:00, P2/EG
Low temperature suppression of the critical current in nanoscale Josephson junction parallel arrays — •Konrad Dapper1, Lukas Powalla1,2, Yannick Schön1, Micha Wildermuth1, Hannes Rotzinger1,3, and Alexey V. Ustinov1,4 — 1Institue of physics, Karlsruhe Institute of Technology, Karlsruhe, Germany — 2Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany — 3Institut für Festköperphysik, Karlsruhe Institute of Technology, Karlsruhe, Germany — 4Russian Quantum Center, National University of Science and Technology MISIS, Moscow, Russia
We investigate the dynamics of fluxoids in parallel arrays of discrete, nanoscale Josephson junctions (JJPA) in the quantum regime where both charging and Josephson energy exceed the thermal energy. One mayor problem of these circuits is the confinement of current vortices in the array, since the small size of the Josephson junctions also leads to a vortex size typically much larger than the array length. To overcome this issue, we place additional Josephson junctions as kinetic inductance elements to each individual plaquette. Special care has also been taken to ensure a homogeneous biasing scheme of the array and a high impedance environment. The arrays are analyzed with transport measurements, in particular, we perform switching current measurements at various milli-Kelvin temperatures. We present data, which show a critical current suppression below temperatures of 600 mK, which indicates an influence of non-thermal quasiparticles and / or quantum phase slips.