title: Generic mechanism for generating a liquid-liquid phase transition.
abstract: Recent experimental results indicate that phosphorus--a single-component system--can have a high-density liquid (HDL) and a low-density liquid (LDL) phase. A first-order transition between two liquids of different densities is consistent with experimental data for a variety of materials, including single-component systems such as water, silica and carbon. Molecular dynamics simulations of very specific models for supercooled water, liquid carbon and supercooled silica predict a LDL-HDL critical point, but a coherent and general interpretation of the LDL-HDL transition is lacking. Here we show that the presence of a LDL and a HDL can be directly related to an interaction potential with an attractive part and two characteristic short-range repulsive distances. This kind of interaction is common to other single-component materials in the liquid state (in particular, liquid metals), and such potentials are often used to describe systems that exhibit a density anomaly. However, our results show that the LDL and HDL phases can occur in systems with no density anomaly. Our results therefore present an experimental challenge to uncover a liquid-liquid transition in systems like liquid metals, regardless of the presence of a density anomaly.
authors.affiliation: Center for Polymer Studies and Department of Physics, Boston University, Massachusetts 02215, USA. franzese@argento.bu.edu
authors.forename: G
authors.initials: G
authors.lastname: Franzese
authors.forename: G
authors.initials: G
authors.lastname: Malescio
authors.forename: A
authors.initials: A
authors.lastname: Skibinsky
authors.forename: S V
authors.initials: SV
authors.lastname: Buldyrev
authors.forename: H E
authors.initials: HE
authors.lastname: Stanley