One-Dimensional Self-Organization and Nonequilibrium Phase Transition in a Hamiltonian System

TL;DR

This paper provides numerical evidence that self-organization and nonequilibrium phase transitions occur in a one-dimensional Hamiltonian system, revealing new insights into transport phenomena in low-dimensional physics.

Contribution

It demonstrates the occurrence of phase transitions and self-organization in a 1D Hamiltonian system, a phenomenon previously known only in higher-dimensional dissipative systems.

Findings

Heat conductivity increases with system size below critical temperature difference.

A phase transition occurs at a critical temperature difference, leading to diverging heat conductivity.

Ordered structures emerge in the system beyond the critical point.

Abstract

Self-organization and nonequilibrium phase transitions are well known to occur in two- and three- dimensional dissipative systems. Here, instead, we provide numerical evidence that these phenomena also occur in a one-dimensional Hamiltonian system. To this end, we calculate the heat conductivity by coupling the two ends of our system to two heat baths at different temperatures. It is found that when the temperature difference is smaller than a critical value, the heat conductivity increases with the system size in power law with an exponent considerably smaller than 1. However, as the temperature difference exceeds the critical value, the system's behavior undergoes a transition and the heat conductivity tends to diverge linearly with the system size. Correspondingly, an ordered structure emerges. These findings suggest a new direction for exploring the transport problems in one dimension.