Berlin 2005 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 2: Poster Quantengase
Q 2.8: Poster
Freitag, 4. März 2005, 11:00–12:30, Poster HU
Macroscopic Quantum Tunneling — •O. Crasser1, R. Kleiner2, E. Goldobin3, K. Vogel1, R. Walser1, and W. P. Schleich1 — 1Abteilung für Quantenphysik, Universität Ulm, 89069 Ulm, Germany — 2Physikalisches Institut-Experimentalphysik II, Universität Tübingen, 72076 Tübingen, Germany — 3Oxxel GmbH, Technologiepark Universität, Bremen 28359, Germany
Tunneling in single particle physics is a well-studied phenomenon, as is
the analogous effect that occurs in quantum fluids [1] and
superconductivity [2]. However, the practical difficulty in theory
arises from the transition from one quantized degree of freedom to
having to deal with infinitely many. In this contribution, we are
examining an excited state of a stationary BEC as described by the
elementary Gross-Pitaevskii mean-field theory. By disregarding the
inherent quantum fluctuations of the bosonic matter wave, this state
would be preserved indefinitely. However, a more elaborate description
leads to a macroscopic quantum tunneling towards the true ground state
of the system.
In the context of atomic Bose gases, this phenomenon was recently
investigated experimentally in [1] and there are strong efforts to
examine the behaviour of "classical" fluxons as well as semifluxons
into the quantum regime as well.
[1] Y. Shin et al., Distillation of Bose-Einstein condensates in
a double-well potential, Phys. Rev. Lett. 92, 150401 (2004)
[2] W. Buckel and R. Kleiner, Superconductivity: Fundamentals
and applications, Wiley-VCH, Berlin (2004)