Düsseldorf 2007 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 52: Quantengase (Tunneln II)

Q 52.1: Talk

Thursday, March 22, 2007, 12:00–12:15, 6J

Collective and Quantum Dynamics in 0-π Josephson Junctions — •Oliver Crasser, Reinhold Walser, and Wolfgang P. Schleich — Institut für Quantenphysik, Universität Ulm, 89069 Ulm

A fluxon is the quantized magnetic flux in a single one-dimensional superconducting junction. By subdividing this junction into a 0 and a π domain, we obtain a 0-π junction. Now, semifluxons are localized phase jumps at the 0-π interface and are an intensively investigated subject of superconductivity [1,2].

In this presentation, we will examine an analogous system, implemented with cold bosonic quantum gases (BEC), using a double well potential as well as a phase dependent Rabi coupling, which leads to a four-mode model. We will shortly discuss the semi-classical equilibrium configuration which is doubly degenerated. Within the four-dimensional Fock space we study various quantum mechanical features such as macroscopic tunneling.

[1] W. Buckel and R. Kleiner, Superconductivity: Fundamentals and applications, Wiley-VCH, Berlin (2004)

[2] E. Goldobin et al., Phys. Rev. B 72, 054527 (2005)