Seminars of the Focus Area Complex Systems

Prof. Dr. C. Beta, Prof. Dr. K. Dethloff, Prof. Dr. R. Engbert, Prof. Dr. M. Holschneider, Prof. Dr. W. Huisinga, Prof. Dr. Ralf Metzler, Prof. Dr. A. Pikovsky, Prof. Dr. S. Reich, Prof. Dr. M. Rosenblum, Prof. Dr. G. Rüdiger, Prof. Dr. T. Scheffer, Prof. Dr. F. Scherbaum, Prof. Dr. J. Selbig, Prof. Dr. F. Spahn

Seminar

Speaker: A. Straube, HU Berlin

Title: Pattern formation in colloidal explosions

Time: Jan 21, 2010, 3:15

Place: Building 28, Room 2.100

Abstract:
We study the non-equilibrium pattern formation in exploding quasi-one-dimensional colloidal chains. Experimentally, superparamagnetic colloidal particles are trapped using optical tweezers at different external magnetic fields which induces a dipolar repulsion between the colloids. Subsequently, removing the optical traps results in a colloidal explosion leading to zigzag pattern formation.

A theoretical analysis shows that a transition from a non-zigzag to a zigzag state is possible for certain traps only and occurs at a critical parameter that characterizes the ratio of magnetic and optical forces. Although the experimental system is always in the non-zigzag state, the explosion demonstrates a zigzag pattern that is very similar to the pattern formation from the equilibrium zigzag state as shown by computer simulation. We ascribe this to the softening of the transverse normal mode band upon approaching the zigzag transition.

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Past NLD Seminars (1994-2007) & (2008 ...)

Students' seminar: Theoretical Physics, PIK, Modeling & TSA Berlin-Potsdam-Colloquia: PhysGesellschaft Berlin, TU Berlin, Pro Physik, AIP, AEI, MPI-KGF, GFZ, HMI, PIK, AWI, Max Planck Institute for the History of Science, Mathematik, DPG Disputationen, & Vorschau UP

Udo Schwarz, Zentrum für Dynamik komplexer Systeme,
Universität Potsdam, Campus Golm Karl-Liebknecht-Str. 24, 14476 Potsdam, building 28, room 2.107
Phone: (+49-331) 977-1658, Fax : (+49-331) 977-1045

Email: Udo.Schwarz AT uni-potsdam.de

DFG SFB 1294

DFG Sonderforschungsbereich 1294 Data assimilation

DFG SPP 1488

DFG Schwerpunktprogramm 1488 Planetmag


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