Probing an excited-state quantum phase transition in a quantum many body system via out-of-time-ordered correlator

Out-of-time-order correlators (OTOCs) play an increasingly important role in different fields of physics and in particular they provide a way of quantifying information scrambling in quantum many-body systems. We verify that an OTOC can be used to probe an excited-state quantum phase transition (ESQ...

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Detalles Bibliográficos
Autores: Wang, Qian, Pérez Bernal, Francisco
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universidad de Huelva (UHU)
Repositorio:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Idioma:inglés
OAI Identifier:oai:ariasmontano.uhu.es:10272/15802
Acceso en línea:http://hdl.handle.net/10272/15802
Access Level:acceso abierto
Palabra clave:Quantum phase transitions
Quantum many body system
Descripción
Sumario:Out-of-time-order correlators (OTOCs) play an increasingly important role in different fields of physics and in particular they provide a way of quantifying information scrambling in quantum many-body systems. We verify that an OTOC can be used to probe an excited-state quantum phase transition (ESQPT) in a quantum many-body system. We examine the dynamical properties of an OTOC in the Lipkin-Meshkov-Glick model, which undergoes an ESQPT, using the exact diagonalization method. We show that the long-time evolution of the proposed OTOC is remarkably different in the different phases of the ESQPT. In consequence, we put the long-time averaged value of the OTOC forward as a possible ESQPT order parameter. Our results highlight the connections between OTOCs and ESQPTs, opening the possibility of using OTOCs for accessing experimentally ESQPTs in quantum many-body systems.