Localization measures of parity adapted U($D$)-spin coherent states applied to the phase space analysis of the $D$-level Lipkin-Meshkov-Glick model

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Mayorgas, Alberto, Guerrero, Julio, Calixto, Manuel
Natura: Preprint
Pubblicazione: 2023
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866908814521925632
author Mayorgas, Alberto
Guerrero, Julio
Calixto, Manuel
author_facet Mayorgas, Alberto
Guerrero, Julio
Calixto, Manuel
contents We study phase-space properties of critical, parity symmetric, $N$-quDit systems undergoing a quantum phase transition (QPT) in the thermodynamic $N\to\infty$ limit. The $D=3$ level (qutrit) Lipkin-Meshkov-Glick (LMG) model is eventually examined as a particular example. For this purpose, we consider U$(D)$-spin coherent states (DSCS), generalizing the standard $D=2$ atomic coherent states, to define the coherent state representation $Q_ψ$ (Husimi function) of a symmetric $N$-quDit state $|ψ>$ in the phase space $\mathbb CP^{D-1}$ (complex projective manifold). DSCS are good variational aproximations to the ground state of a $N$-quDit system, specially in the $N\to\infty$ limit, where the discrete parity symmetry $\mathbb{Z}_2^{D-1}$ is spontaneously broken. For finite $N$, parity can be restored by projecting DSCS onto $2^{D-1}$ different parity invariant subspaces, which define generalized ``Schrödinger cat states'' reproducing quite faithfully low-lying Hamiltonian eigenstates obtained by numerical diagonalization. Precursors of the QPT are then visualized for finite $N$ by plotting the Husimi function of these parity projected DSCS in phase space, together with their Husimi moments and Wehrl entropy, in the neighborhood of the critical points. These are good localization measures and markers of the QPT.
format Preprint
id arxiv_https___arxiv_org_abs_2302_06254
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Localization measures of parity adapted U($D$)-spin coherent states applied to the phase space analysis of the $D$-level Lipkin-Meshkov-Glick model
Mayorgas, Alberto
Guerrero, Julio
Calixto, Manuel
Quantum Physics
Mathematical Physics
Nuclear Theory
We study phase-space properties of critical, parity symmetric, $N$-quDit systems undergoing a quantum phase transition (QPT) in the thermodynamic $N\to\infty$ limit. The $D=3$ level (qutrit) Lipkin-Meshkov-Glick (LMG) model is eventually examined as a particular example. For this purpose, we consider U$(D)$-spin coherent states (DSCS), generalizing the standard $D=2$ atomic coherent states, to define the coherent state representation $Q_ψ$ (Husimi function) of a symmetric $N$-quDit state $|ψ>$ in the phase space $\mathbb CP^{D-1}$ (complex projective manifold). DSCS are good variational aproximations to the ground state of a $N$-quDit system, specially in the $N\to\infty$ limit, where the discrete parity symmetry $\mathbb{Z}_2^{D-1}$ is spontaneously broken. For finite $N$, parity can be restored by projecting DSCS onto $2^{D-1}$ different parity invariant subspaces, which define generalized ``Schrödinger cat states'' reproducing quite faithfully low-lying Hamiltonian eigenstates obtained by numerical diagonalization. Precursors of the QPT are then visualized for finite $N$ by plotting the Husimi function of these parity projected DSCS in phase space, together with their Husimi moments and Wehrl entropy, in the neighborhood of the critical points. These are good localization measures and markers of the QPT.
title Localization measures of parity adapted U($D$)-spin coherent states applied to the phase space analysis of the $D$-level Lipkin-Meshkov-Glick model
topic Quantum Physics
Mathematical Physics
Nuclear Theory
url https://arxiv.org/abs/2302.06254