Confocal Annular Josephson Tunnel Junctions with Large Eccentricity

Journal Article · Sat Sep 15 04:00:00 EDT 2018 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/S10909-018-1977-1· OSTI ID:22809997

Monaco, Roberto ^[1]; Mygind, Jesper ^[2]

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1. CNR-ISASI, Institute of Applied Sciences and Intelligent Systems “E. Caianello” (Italy)
2. Technical University of Denmark, DTU Physics, B309 (Denmark)

Confocal annular Josephson tunnel junctions (CAJTJs), which are the natural generalization of the circular annular Josephson tunnel junctions, have a rich nonlinear phenomenology due to the intrinsic non-uniformity of their planar tunnel barrier delimited by two closely spaced confocal ellipses. In the presence of a uniform magnetic field in the barrier plane, the periodically changing width of the elliptical annulus generates a asymmetric double-well for a Josephson vortex trapped in a long and narrow CAJTJ. The preparation and readout of the vortex pinned in one of the two potential minima, which are important for the possible realization of a vortex qubit, have been numerically and experimentally investigated for CAJTJs with the moderate aspect ratio 2:1. In this work, we focus on the impact of the annulus eccentricity on the properties of the vortex potential profile and study the depinning mechanism of a fluxon in more eccentric samples with aspect ratio 4:1. We also discuss the effects of the temperature-dependent losses as well as the influence of the current and magnetic noise.

• OSTI ID: 22809997
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 5-6 Vol. 192; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ASPECT RATIO
MAGNETIC FIELDS
NONLINEAR PROBLEMS
POTENTIALS
QUANTUM COMPUTERS
QUBITS
TEMPERATURE DEPENDENCE
TUNNEL JUNCTIONS