Construction and simulability of quantum circuits with free fermions in disguise

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Szász-Schagrin, Dávid, Cristani, Daniele, Piroli, Lorenzo, Vernier, Eric
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911403167711232
author Szász-Schagrin, Dávid
Cristani, Daniele
Piroli, Lorenzo
Vernier, Eric
author_facet Szász-Schagrin, Dávid
Cristani, Daniele
Piroli, Lorenzo
Vernier, Eric
contents We provide a systematic construction for local quantum circuits hosting free fermions in disguise, both with staircase and brickwork architectures. Similar to the original Hamiltonian model introduced by Fendley, these circuits are defined by the fact that the Floquet operator corresponding to a single time step can not be diagonalized by means of any Jordan-Wigner transformation, but still displays a free-fermionic spectrum. Our construction makes use of suitable non-local transfer matrices commuting with the Floquet operator, allowing us to establish the free fermionic spectrum. We also study the dynamics of these circuits after they are initialized in arbitrary product states, proving that the evolution of certain local observables can be simulated efficiently on classical computers. Our work proves recent conjectures in the literature and raises new questions on the classical simulability of free fermions in disguise.
format Preprint
id arxiv_https___arxiv_org_abs_2509_22585
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Construction and simulability of quantum circuits with free fermions in disguise
Szász-Schagrin, Dávid
Cristani, Daniele
Piroli, Lorenzo
Vernier, Eric
Quantum Physics
Statistical Mechanics
Mathematical Physics
We provide a systematic construction for local quantum circuits hosting free fermions in disguise, both with staircase and brickwork architectures. Similar to the original Hamiltonian model introduced by Fendley, these circuits are defined by the fact that the Floquet operator corresponding to a single time step can not be diagonalized by means of any Jordan-Wigner transformation, but still displays a free-fermionic spectrum. Our construction makes use of suitable non-local transfer matrices commuting with the Floquet operator, allowing us to establish the free fermionic spectrum. We also study the dynamics of these circuits after they are initialized in arbitrary product states, proving that the evolution of certain local observables can be simulated efficiently on classical computers. Our work proves recent conjectures in the literature and raises new questions on the classical simulability of free fermions in disguise.
title Construction and simulability of quantum circuits with free fermions in disguise
topic Quantum Physics
Statistical Mechanics
Mathematical Physics
url https://arxiv.org/abs/2509.22585