Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.13: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
Sr2Cu(PO4)2: A real material realization of the 1D nearest neighbor Heisenberg chain — •M.D. Johannes1, J. Richter2, S.-L. Drechsler3, A. A. Belik4, E. Takayama-Muromachi4, S. Uji4, and H. Rosner5 — 1Naval Research Laboratory, Washington D.C — 2Institute for Theoretical Physics, Magdeburg, Germany — 3Liebnitz Institute for Solid State and Materials Research, Dresden, Germany — 4National Institute for Materials Science, Ibaraki, Tsukuba, Japan — 5Max-Planck Institute for Chemical Physics of Solids, Dresden, Germany
The search for one-dimensional magnets began with the advent of quantum mechanics and the discovery that fluctuation effects, enhanced by low-dimensionality, could lead to novel ground states and exotic effects not accessible in higher dimensions. We present evidence that Sr2Cu(PO4)2 is a nearly perfect one-dimensional (1D) spin 1/2 Heisenberg chain with nearest neighbor only interactions. Combining experimental measurements down to T=30mK with first principles and model calculations, we demonstrate that the one dimensionality of Sr2Cu(PO4)2, as measured by the ratio kBTN/J1, exceeds that of prototype 1D compound Sr2CuO3 by an order of magnitude. Surprisingly, Sr2Cu(PO4)2 lacks clear structural chains, achieving magnetic one-dimensionality instead via isolated CuO4 plaquettes coupled along a single direction. This unusual geometry also strongly suppresses frustrating interactions between second neighbors along the spin chain direction, thereby providing an ideal physical realization of an exactly solvable theoretical model.