Novel low-temperature behavior in classical many-particle systems.
We show that classical many-particle systems interacting with certain soft pair interactions in two dimensions exhibit novel low-temperature behaviors. Ground states span from disordered to crystalline. At some densities, a large fraction of normal-mode frequencies vanish. Lattice ground-state configurations have more vanishing frequencies than disordered ground states at the same density and exhibit vanishing shear moduli. For the melting transition from a crystal, the thermal expansion coefficient is negative. These unusual results are attributed to the topography of the energy landscape.
Department of Chemical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Robert D
RD
Batten
Frank H
FH
Stillinger
Salvatore
S
Torquato