Free fermionic and parafermionic multispin quantum chains with non-homogeneous interacting ranges

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Alcaraz, Francisco C.
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914535298826240
author Alcaraz, Francisco C.
author_facet Alcaraz, Francisco C.
contents A large family of multispin interacting one-dimensional quantum spin models with $Z(N)$ symmetry and a free-particle eigenspectra are known in the literature. They are free-fermionic ($N=2$) and free-parafermionic ($N\geq 2$) quantum chains. The essential ingredient that implies the free-particle spectra is the fact that these Hamiltonians are expressed in terms of generators of a $Z(N)$ exchange algebra. In all these known quantum chains the number of spins in all the multispin interactions (range of interactions) is the same and therefore, the models have homogeneous interacting range. In this paper we extend the $Z(N)$ exchange algebra, by introducing new models with a free-particle spectra, where the interaction ranges of the multispin interactions are not uniform anymore and depends on the lattice sites (non-homogeneous interacting range). We obtain the general conditions that the site-dependent ranges of the multispin interactions have to satisfy to ensure a free-particle spectra. Several simple examples are introduced. We study in detail the critical properties in the case where the range of interactions of the even (odd) sites are constant. The dynamical critical exponent is evaluated in several cases.
format Preprint
id arxiv_https___arxiv_org_abs_2512_08011
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Free fermionic and parafermionic multispin quantum chains with non-homogeneous interacting ranges
Alcaraz, Francisco C.
Statistical Mechanics
A large family of multispin interacting one-dimensional quantum spin models with $Z(N)$ symmetry and a free-particle eigenspectra are known in the literature. They are free-fermionic ($N=2$) and free-parafermionic ($N\geq 2$) quantum chains. The essential ingredient that implies the free-particle spectra is the fact that these Hamiltonians are expressed in terms of generators of a $Z(N)$ exchange algebra. In all these known quantum chains the number of spins in all the multispin interactions (range of interactions) is the same and therefore, the models have homogeneous interacting range. In this paper we extend the $Z(N)$ exchange algebra, by introducing new models with a free-particle spectra, where the interaction ranges of the multispin interactions are not uniform anymore and depends on the lattice sites (non-homogeneous interacting range). We obtain the general conditions that the site-dependent ranges of the multispin interactions have to satisfy to ensure a free-particle spectra. Several simple examples are introduced. We study in detail the critical properties in the case where the range of interactions of the even (odd) sites are constant. The dynamical critical exponent is evaluated in several cases.
title Free fermionic and parafermionic multispin quantum chains with non-homogeneous interacting ranges
topic Statistical Mechanics
url https://arxiv.org/abs/2512.08011