On the nature of striped phases: Striped phases as a stage of "melting" of 2D crystals

We discuss striped phases as a state of matter intermediate between two extreme states: a crystalline state and a segregated state. We argue that this state is very sensitive to weak interactions, compared to those stabilizing a crystalline state, and to anisotropies. Moreover, under suitable conditions a 2D system in a striped phase decouples into (quasi) 1D chains. These observations are based on results of our studies of an extension of a microscopic quantum model of crystallization, proposed originally by Kennedy and Lieb.Comment: 16 pages, 8 figure

Towards a quasiphase transition in the single-file chain of water molecules: Simple lattice model

Recently, X.Ma et al. [Phys. Rev. Lett. 118, 027402 (2017)] have suggested that water molecules encapsulated in (6,5) single-wall carbon nanotube experience a temperature-induced quasiphase transition around 150 K interpreted as changes in the water dipoles orientation. We discuss further this temperature-driven quasiphase transition performing quantum chemical calculations and molecular dynamics simulations and, most importantly, suggesting a simple lattice model to reproduce the properties of the one-dimensionally confined finite arrays of water molecules. The lattice model takes into account not only the short-range and long-range interactions but also the rotations in a narrow tube and the both ingredients provide an explanation for a temperature-driven orientational ordering of the water molecules, which persists within a relatively wide temperature range.Comment: 15 pages, 10 figure