Hannover 2013 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 35: Poster I
Q 35.40: Poster
Tuesday, March 19, 2013, 16:00–18:30, Empore Lichthof
Trapping of Topological-Structural Defects in Coulomb Crystals — •Manuel Mielenz1, Jonathan Brox1, Haggai Landa2, Steffen Kahra1, Guenther Leschhorn1, Magnus Albert1, Benni Reznik2, and Tobias Schaetz1 — 1Physikalisches Institut, Albert-Ludwigs Universität Freiburg — 2School of Physics and Astronomy, Tel-Aviv University
We study experimentally and theoretically structural defects which are formed during the transition from a laser cooled cloud to a Coulomb crystal, consisting of tens of ions in a linear radiofrequency trap. We demonstrate the creation of predicted topological defects (‘kinks’) [1, 2, 3] in purely two-dimensional crystals, and also find kinks which show novel dynamical features in a regime of parameters not considered before. The kinks are always observed at the centre of the trap, showing a large nonlinear localized excitation, and the probability of their occurrence surprisingly saturates at ∼ 0.5. Simulations reveal a strong anharmonicity of the kink’s internal mode of vibration, due to the kink’s extension into three dimensions. As a consequence, the periodic Peierls-Nabarro potential experienced by a discrete kink becomes a globally confining potential, capable of trapping one cooled defect at the center of the crystal.
[1] H. Landa et al., PRL 104, 043004 (2010)
[2] Ch. Schneider et al., Rep. Prog. Phys. 75, 024401 (2012)
[3] M. Mielenz et al., submitted to PRL