Ground-state separability and criticality in interacting many-particle systems

We analyze exact ground state (GS) separability in general N-particle systems with two-site couplings. General necessary and sufficient conditions for full separability in the form of one- and two-site eigenvalue equations are first derived. The formalism is then applied to a class of SU(n)-type int...

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Detalles Bibliográficos
Autores: Petrovich, Federico, Canosa, Norma Beatriz, Rossignoli, Raúl Dante
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/209505
Acceso en línea:http://hdl.handle.net/11336/209505
Access Level:acceso abierto
Palabra clave:Quantum Criticality
Quantum Entanglement
Quantum Phase Transitions
Quantum Spin Models
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:We analyze exact ground state (GS) separability in general N-particle systems with two-site couplings. General necessary and sufficient conditions for full separability in the form of one- and two-site eigenvalue equations are first derived. The formalism is then applied to a class of SU(n)-type interacting systems where each constituent has access to n-local levels, and where the total number parity of each level is preserved. Explicit factorization conditions for parity-breaking GSs are obtained, which generalize those for XYZ spin systems and correspond to a fundamental GS multilevel parity transition where the lowest 2n-1 energy levels cross. We also identify a multicritical factorization point with exceptional high degeneracy proportional to Nn-1, arising when the total occupation number of each level is preserved, in which any uniform product state is an exact GS. Critical entanglement properties (such as full range pairwise entanglement) are shown to emerge in the immediate vicinity of factorization. Illustrative examples are provided.