Dresden 2011 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 57: Poster 3: Quantengase, Ultrakalte Atome, Ultrakalte Moleküle, Materiewellen Optik, Präzisionsmessungen, Metrologie
Q 57.24: Poster
Thursday, March 17, 2011, 16:30–19:30, P1
Spontaneous Breaking of Spatial and Spin Symmetry in Spinor Condensates — Manuel Scherer1, Bernd Lücke1, •Jan Peise1, Garu Gebreyesus2, Oliver Topic1, Frank Deuretzbacher2, Wolfgang Ertmer1, Luis Santos2, Jan Arlt3, and Carsten Klempt1 — 1Institut für Quantenoptik, Leibniz Universität Hannover, 30167 Hannover, Germany — 2Institut für Theoretische Physik, Leibniz Universität Hannover, 30167 Hannover, Germany — 3QUANTOP, Department of Physics and Astronomy, University of Aarhus, 8000 Århus C, Denmark
Spin-changing collisions can be utilized as parametric amplification of quantum fluctuations, a fundamental mechanism for spontaneous symmetry breaking. We realize a parametric amplifier for spin modes by a spinor Bose-Einstein condensate, resulting in a twofold spontaneous breaking of spatial and spin symmetry in the amplified clouds. Our experiment provides a precise analysis of the amplification of spatial Bessel-like modes, and a detailed understanding of the twofold symmetry breaking. On magnetic resonances that create vortex-antivortex superpositions, we demonstrate that the cylindrical spatial symmetry is spontaneously broken. However, spin symmetry is preserved as a consequence of phase squeezing. If nondegenerate spin modes contribute to the amplification, quantum interferences produce spin-dependent density profiles and lead to spontaneously formed patterns in the longitudinal magnetization.