The interplay between liquid-liquid and ferroelectric phase transitions in supercooled water

TL;DR

This paper explores the connection between ferroelectric and liquid-liquid phase transitions in supercooled water, supported by molecular dynamics simulations and a classical density functional theory, suggesting ferroelectricity influences water's phase behavior.

Contribution

It demonstrates that ferroelectric and liquid-liquid phase transitions are interconnected phenomena in supercooled water, supported by simulations and theoretical analysis.

Findings

Confirmation of ferroelectric order in supercooled water

Observation of polarization fluctuation modes in simulations

Theoretical link between ferroelectricity and phase transition

Abstract

The distinctive characteristics of water, evident in its thermodynamic anomalies, have implications across disciplines from biology to geophysics. Considered a valid hypothesis to rationalize its unique properties, a liquid-liquid phase transition in water's supercooled regime has nowadays been observed in several molecular dynamics simulations and is being actively researched experimentally. Here, we highlight intriguing and far-reaching implications of water: the ferroelectric and liquid-liquid phase transitions can be designed as two facets of the same underlying phenomenon. Our results are based on the analysis of extensive molecular dynamics simulations and are explained in the context of a classical density functional theory in mean-field approximation valid for a polar liquid. The theory underpins the potential role of ferroelectricity in promoting the liquid-liquid phase transition. The existence of ferroelectric order in supercooled low-density liquid water is confirmed by the observation in molecular dynamics simulations of collective modes in polarization fluctuations dynamics, traceable to spontaneous breaking of continuous rotational symmetry. Our work opens the door to new experimental investigations of the static and dynamic behavior of water polarization.