Crystallization and vitrification of strongly correlated electrons on geometrically frustrated trian

Summary

Recently, we reported a unique glassy state of electrons – in contrast to long-range charge
ordering (CO) – realized in the organic conductor θm-(BEDT-TTF)2TlZn(SCN)4, where the lack
of periodicity of the strongly correlated electrons on the triangular lattice, characterizing
the glassy state, is caused by geometric frustration and strong quantum effects [1]. Our
experiments reveal that the CO transition (charge crystallization) can be avoided by rapid
cooling, and charge vitrification occurs via a supercooled charge-liquid state. This can be
understood by the notion of the energy landscape with multiple local minima caused by
the geometrically frustrated triangular lattice of this system. We also demonstrate that the
crystallization of strongly correlated electrons involves the same nucleation and growth
processes as that of conventional glass-forming liquids such as structural and metallic
glasses. These similarities among different classes of glass formers are surprising and will
constitute further new insights to our general understanding of the liquid-glass transition.

[1] S. Sasaki, K. Hashimoto et al., Science 357, 1381 (2017).