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arXiv · 0811.1236

Counterintuitive ground states in soft-core models

Henry Cohn·Abhinav Kumar
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Abstract

It is well known that statistical mechanics systems exhibit subtle behavior in high dimensions. In this paper, we show that certain natural soft-core models, such as the Gaussian core model, have unexpectedly complex ground states even in relatively low dimensions. Specifically, we disprove a conjecture of Torquato and Stillinger, who predicted that dilute ground states of the Gaussian core model in dimensions 2 through 8 would be Bravais lattices. We show that in dimensions 5 and 7, there are in fact lower-energy non-Bravais lattices. (The nearest three-dimensional analog is the hexagonal close-packing, but it has higher energy than the face-centered cubic lattice.) We believe these phenomena are in fact quite widespread, and we relate them to decorrelation in high dimensions.

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Henry Cohn, Abhinav Kumar. 2008-12-19. Counterintuitive ground states in soft-core models. https://doi.org/10.1103/physreve.78.061113

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