Transient Structured Fluctuations Approaching 2D Kagome-Liquid Transition

We study two 2D systems known to support an open-packed Kagome phase[1]. Both systems have repulsive pair potentials, one designed by Piñeros, Baldea, and Truskett and another by Zhang, Stillinger, and Torquato[2-3]. Using the aperture cross-correlation function (ACCF), we identify structured fluctuations in the liquid phases approaching the Kagome-liquid transition[4]. These Kagome-like fluctuations may be distinguished from hexagonal ones by calculating the ACCF at two different wavevector magnitudes along the second diffraction ring. Fluctuations near a string-Kagome transition involve transient structures that are different for different potentials. We find congruencies in the sequence of phases along an isotherm for many different 2D systems of Hertzian, Lennard-Jones-Yukawa, Core-Corona, and Daoud–Cotton particle potentials. These similarities suggest a universal mechanism among the phase transitions of 2D systems supported by central repulsive potentials.
[1] L. M. Nowack and S. A. Rice. arXiv:1910.02980 [cond-mat.soft] (2019)
[2] W. D. Piñeros et al, J Chem Phys 145, 054901 (2016)
[3] G. Zhang et al, Phys Rev E 88, 042309 (2013)
[4] B. J. Ackerson et al, Phys Rev A, 31, 3183 (1985)