Excited-state quantum phase transitions in the anharmonic Lipkin-Meshkov-Glick model: Static aspects
Metadatos
Mostrar el registro completo del ítemEditorial
American Physical Society
Fecha
2022-10-17Referencia bibliográfica
Gamito, J... [et al.]. Excited-state quantum phase transitions in the anharmonic Lipkin-Meshkov-Glick model: Static aspects. PHYSICAL REVIEW E 106, 044125 (2022). DOI: [10.1103/PhysRevE.106.044125]
Patrocinador
I + D + i Projects - MCIN/AEI PID2019-104002GB-C21 PID2019104002GB-C22 PID2020-114687GB-I00 MCIN/AEI/10.13039/501100011033; Junta de Andalucia; European Commission UHU-1262561 US-1380840; Junta de Andalucia P20_01247; ERDF-A Way of Making Europe European Commission; Spanish Government UNHU-15CE-2848; European Union NextGenerationEU/PRTRResumen
The basic Lipkin-Meshkov-Glick model displays a second-order ground-state quantum phase transition and
an excited-state quantum phase transition (ESQPT). The inclusion of an anharmonic term in the Hamiltonian
implies a second ESQPT of a different nature. We characterize this ESQPT using the mean field limit of the
model. The alternative ESQPT, associated with the changes in the boundary of the finite Hilbert space of
the system, can be properly described using the order parameter of the ground-state quantum phase transition,
the energy gap between adjacent states, the participation ratio, and the quantum fidelity susceptibility.