Integrable spin chains and cellular automata with medium-range interaction

T Gombor, B Pozsgay - Physical Review E, 2021 - APS
We study integrable spin chains and quantum and classical cellular automata with
interaction range ℓ≥ 3. This is a family of integrable models for which there was no general …

Random free-fermion quantum spin chain with multispin interactions

FC Alcaraz, JA Hoyos, RA Pimenta - Physical Review B, 2023 - APS
We study the effects of quenched disorder in a class of quantum chains with (p+ 1)-multispin
interactions exhibiting a free fermionic spectrum, paying special attention to the case p= 2 …

Ising analogs of quantum spin chains with multispin interactions

FC Alcaraz, RA Pimenta, J Sirker - Physical Review B, 2023 - APS
A new family of free fermionic quantum spin chains with multispin interactions was recently
introduced. Here we show that it is possible to build standard quantum Ising chains—but …

A unified graph-theoretic framework for free-fermion solvability

A Chapman, SJ Elman, RL Mann - arXiv preprint arXiv:2305.15625, 2023 - arxiv.org
We show that a quantum spin system has an exact description by non-interacting fermions if
its frustration graph is claw-free and contains a simplicial clique. The frustration graph of a …

Quantum circuits with free fermions in disguise

B Pozsgay - arXiv preprint arXiv:2402.02984, 2024 - arxiv.org
Recently multiple families of spin chain models were found, which have a free fermionic
spectrum, even though they are not solvable by a Jordan-Wigner transformation. Instead, the …

Exceptional points in the Baxter-Fendley free parafermion model

R Henry, M Batchelor - SciPost Physics, 2023 - scipost.org
Certain spin chains, such as the quantum Ising chain, have free fermion spectra which can
be expressed as the sum of decoupled two-level fermionic systems. Free parafermions are a …

[HTML][HTML] A brief history of free parafermions

MT Batchelor, RA Henry, X Lu - AAPPS Bulletin, 2023 - Springer
In this article we outline the historical development and key results obtained to date for free
parafermionic spin chains. The concept of free parafermions provides a natural N-state …

Conformally invariant free-parafermionic quantum chains with multispin interactions

FC Alcaraz, LM Ramos - Physical Review E, 2024 - APS
We calculate the spectral properties of two related families of non-Hermitian free-particle
quantum chains with N-multispin interactions (N= 2, 3,...). The first family have a Z (N) …

Exact real time dynamics with free fermions in disguise

I Vona, M Mestyán, B Pozsgay - arXiv preprint arXiv:2405.20832, 2024 - arxiv.org
We consider quantum spin chains with a hidden free fermionic structure, distinct from the
Jordan-Wigner transformation and its generalizations. We express selected local operators …

Exactly soluble models in many-body physics

S Elman - 2023 - ses.library.usyd.edu.au
Almost all phenomena in the universe are described, at the fundamental level, by quantum
manybody models. In general, however, a complete understanding of large systems with …