Theoretical Physics Seminar:
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Mar 07, 2008 02:00 PM, Theoretical Physics Seminar Room, LC.3.17
Aperiodicity & order
Speaker: Grimm, Uwe
Abstract: A perfect crystal is the paradigm of symmetry and order in nature. Its regular features reflect the underlying order in the atomic arrangement, which is based on a motif that is repeated periodically. The list of possible crystal structures had been known for over a century. So it came as a surprise when, in 1982, new materials, now known as quasicrystals, were discovered which appear to be as well-ordered as crystals, but show symmetries that cannot be reconciled with an underlying periodic pattern. Twenty years later, the arrangement of atoms in quasicrystals is still only partially understood. Aperiodic tilings of space, such as the Penrose tiling, provide idealised mathematical structure models. Quasicrystals not only show interesting physical properties, but also raise some general questions about what we mean by 'order', and what other exotic structures might be realised in nature. In this talk, I shall give an gentle introduction to the mathematics of aperiodic tilings and their application to quasicrystals.
