Ordering kinetics and steady states of XY-model with ferromagnetic and nematic interaction

TL;DR

This paper investigates the dynamic evolution and phase behavior of the generalized XY model with combined ferromagnetic and nematic interactions, revealing temperature-dependent coarsening and a phase diagram with three low-temperature phases.

Contribution

It provides the first detailed analysis of the non-equilibrium kinetics and phase diagram of the XY model with mixed interactions, emphasizing the evolution towards equilibrium.

Findings

Temperature-dependent decay of defect annihilation exponent

Decelerated domain growth at low temperatures

Identification of three low-temperature phases: polar, nematic, and coexistence

Abstract

Previous studies on the generalized XY model have concentrated on the equilibrium phase diagram and the equilibrium nature of distinct phases under varying parameter conditions. We direct our attention towards examining the systems evolution towards equilibrium states across different parameter values, specifically by varying the relative strengths of ferromagnetic and nematic interactions. We study the kinetics of the system, using the temporal annihilation of defects at varying temperatures and its impact on the coarsening behavior of the system. For both pure polar and pure nematic systems, we observe temperature-dependent decay of the exponent, leading to a decelerated growth of domains within the system. At parameter values where both ferromagnetic and nematic interactions are simultaneously present, we show a phase diagram highlighting three low-temperature phases : polar, nematic, and coexistence, alongside a high-temperature disordered phase. Our study provides valuable insights into the complex interplay of interactions, offering a comprehensive understanding of the systems behavior during its evolution towards equilibrium.