Interlinking motifs and entropy landscapes of statistically interacting particles

TL;DR

This paper models a system of statistically interacting particles derived from an Ising chain, revealing how motifs and entropy landscapes govern ordering and structure formation at different temperatures.

Contribution

It introduces a novel particle-based framework linking motifs, entropy, and interactions in an Ising model, highlighting multi-level structures and ordering mechanisms.

Findings

Particles remain interaction-free at high density.

Entropy depends on particle populations and motifs.

Structures emerge from particle interactions and long-range order.

Abstract

The s=1/2 Ising chain with uniform nearest-neighbor and next-nearest-neighbor coupling is used to construct a system of floating particles characterized by motifs of up to six consecutive local spins. The spin couplings cause the assembly of particles which, in turn, remain free of interaction energies even at high density. All microstates are configurations of particles from one of three different sets, excited from pseudo-vacua associated with ground states of periodicities one, two, and four. The motifs of particles and elements of pseudo-vacuum interlink in two shared site variables. The statistical interaction between particles is encoded in a generalized Pauli principle, describing how the placement of one particle modifies the options for placing further particles. In the statistical mechanical analysis arbitrary energies can be assigned to all particle species. The entropy is a function of the particle populations. The statistical interaction specifications are transparently built into that expression. The energies and structures of the particles alone govern the ordering at low temperature. Under special circumstances the particles can be replaced by more fundamental particles with shorter motifs that interlink in only one shared site variable. Structures emerge from interactions on two levels: particles with shapes from coupled spins and long-range ordering tendencies from statistically interacting particles with shapes.