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G. Kahl:
"Tunability and order: the plethora of polymorphism of Wigner bilayer systems";
Talk: CONIN Workshop, Jablonna Palace, Polen; 02-17-2017 - 02-20-2017; in: "Systems with competing electrostatic and short-range interactions", (2017), 11.

Self-assembly into target structures is an efficient strategy of materials design. In our problem we consider an ensemble of mobile point charges (carrying nominal charges −e) that are confined between two parallel plates; these plates are separated by a distance η and bear uniform charge densities σ1e and σ2e, with A = σ2=σ1. Combining complementary theoretical approaches (i.e., analytical calculations, computational techniques based on evolutionary algorithms, and Monte Carlo simulations) we provide a comprehensive diagram of ordered ground state configurations of the charges as we systematically vary the asymmetry parameter A and the plate separation η [1]. The complex interplay between structural commensurability requirements and charge neutralization leads to a plethora of exotic Wigner bilayer ground state configurations (among those Archimedean tilings or pentagonal structures). Further we observe long-range attractions between the plates, the appearance of macroscopic charges, and the emergence of
non-conventional phase transitions, pertaining to different universality classes. The simplicity
of the system offers the possibility to conveniently and precisely control these features via the two external parameters, A and η.

1. M. Antlanger, G. Kahl, M. Mazars, L. Samaj, and E. Trizac, Phys. Rev. Lett 117 118002 (2016)

http://publik.tuwien.ac.at/files/publik_266994.pdf

Project Head Gerhard Kahl:
DFS