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MM: Fachverband Metall- und Materialphysik

MM 40: Quasicrystals I

MM 40.3: Vortrag

Donnerstag, 26. März 2009, 10:45–11:00, IFW D

In search of multipolar order on the Penrose tiling — •Elena Y. Vedmedenko¹, Ron Lifshitz², and S. Even-Dar Mandel² — ¹University of Hamburg, Jungiusstr. 11, 20355 Hamburg — ²Tel Aviv University, 69978 Tel Aviv, Israel

We use Monte Carlo calculations to analyse multipolar ordering on the Penrose tiling, relevant for two-dimensional molecular adsorbates on quasicrystalline surfaces and for nanomagnetic arrays. Our initial investigations are restricted to multipolar rotors of rank one through four positioned on the vertices of the rhombic Penrose tiling. At first sight, the ground states of odd-parity multipoles seem to exhibit long-range order, in agreement with previous investigations of dipolar systems. Yet, careful analysis performed here establishes that long-range order is absent for all types of rotors, and only short-range order exists. Nevertheless, we show here that short-range order suffices to yield a superstructure in the form of the decagonal Hexagon-Boat-Star tiling. [1] E. Y. Vedmedenko, S. Even-Dar Mandelb and R. Lifshitz, Phil. Mag. 88, 2197 (2008).