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Type: 
Journal
Description: 
We study the quantum metric tensor and its scalar curvature for a particular version of the Lipkin-Meshkov-Glick model. We build the classical Hamiltonian using Bloch coherent states and find its stationary points. They exhibit the presence of a ground-state quantum phase transition where a bifurcation occurs, showing a change in stability associated with an excited-state quantum phase transition. Symmetrically, for a sign change in one Hamiltonian parameter, the same phenomenon is observed in the highest-energy state. Employing the Holstein-Primakoff approximation, we derive analytic expressions for the quantum metric tensor and compute the scalar and Berry curvatures. We contrast the analytic results with their finite-size counterparts obtained through exact numerical diagonalization and find excellent agreement between them for large sizes of the system in a wide region of the parameter space except in …
Publisher: 
American Physical Society
Publication date: 
10 May 2021
Authors: 

Daniel Gutiérrez-Ruiz, Diego Gonzalez, Jorge Chávez-Carlos, Jorge G Hirsch, J David Vergara

Biblio References: 
Volume: 103 Issue: 17 Pages: 174104
Origin: 
Physical Review B