Who will see the first swan in a see of phonons ?
2014 was the international year of crystallography. In the middle of this very same year was prepublished a speculative research article by Latham Boyle and two coworkers about a natural dynamical analogue of crystalline order named choreographic order by the three scientists. It took them some time to publish this work in the prestigious Physical Review Letter but that was accomplished in January 2016. Here what it talks about:
Symmetric Satellite Swarms and Choreographic Crystals
Latham Boyle, Jun Yong Khoo, Kendrick Smith
(Submitted on 22 Jul 2014 (v1), last revised 8 Jan 2016 (this version, v2))
In this paper, we introduce a natural dynamical analogue of crystalline order, which we call choreographic order. In an ordinary (static) crystal, a high degree of symmetry may be achieved through a careful arrangement of the fundamental repeated elements. In the dynamical analogue, a high degree of symmetry may be achieved by having the fundamental elements perform a carefully choreographed dance. For starters, we show how to construct and classify all symmetric satellite constellations. Then we explain how to generalize these ideas to construct and classify choreographic crystals more broadly. We introduce a quantity, called the "choreography" of a given configuration. We discuss the possibility that some (naturally occurring or artificial) many-body or condensed-matter systems may exhibit choreographic order, and suggest natural experimental signatures that could be used to identify and characterize such systems.
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| The 2D planar choreographic crystal of highest choreography (top), and another close contender (bottom). Each arrow shows the initial position and velocity of a point that proceeds to move along a straight line (i.e. a geodesic in Euclidean space). Under each crystal, we have shown a colored tiling meant to help the reader see how the dance proceeds (from blue to yellow to pink, in repeating pattern). |
This new year 2016 why not celebrate the centenary of the beginning of the elaboration of the valence bond by Gilbert Newton Lewis with his famous article the Atom and the Molecule?
