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TT: Fachverband Tiefe Temperaturen
TT 15: Superconductivity - Tunneling, Josephson Junctions, SQUIDs
TT 15.6: Hauptvortrag
Dienstag, 27. März 2007, 15:30–16:00, H20
Fractional flux quanta in Josephson junctions — •Edward Goldobin1, Kai Buckenmaier1, Tobias Gaber1, Matthias Kemmler1, Martin Weides2, Judith Pfeiffer1, Hermann Kohlstedt2, Dieter Koelle1, Reinhold Kleiner1, and Michael Siegel3 — 1Physikalisches Institut – Experimentalphysik II, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany — 2Center of Nanoelectronic Systems for Information Technology (CNI), Research Centre Jülich, D-52425 Jülich, Germany — 3Institut für Mikro– und Nanoelektronische Systeme, Universität Karlsruhe, Hertzstr. 16, D-76187 Karlsruhe, Germany
Fractional Josephson vortices may appear in the so-called 0-κ Josephson junctions (κ is an arbitrary number) and carry magnetic flux Φ, which is a fraction of the magnetic flux quantum Φ0≈ 2.07×10−15 Wb. Their properties are very different from the usual integer fluxons: they are pinned, and often represent the ground state of the system with spontaneous circulating supercurrent. They behave as well controlled macroscopic spins and can be used to construct bits, qubits, tunable photonic crystals and to study the (quantum) physics of spin systems.
In this talk we discuss recent advances in 0-π junction technology and present recent experimental results: evidence of the spontaneous flux in the ground state[1], spectroscopy of the fractional vortex eigenfrequencies[2] and observation of dynamics effects related to the flipping of the fractional vortices.
[1] M. Weides et al., Phys. Rev. Lett. 97, 247001 (2006).
[2] K. Buckenmaier et al., cond-mat/0610043.