We study finite-temperature topological properties of the Kitaev’s spin-honeycomb model in the vortex-free sector with the use of the recently introduced mean Uhlmann curvature. We employ an appropriate fermionization procedure to study the system as a two-band p-wave superconductor described by a Bogoliubov–de Gennes Hamiltonian. This allows us to study relevant quantities such as Berry and mean Uhlmann curvatures in a simple setting. More specifically, we consider the spin honeycomb in the presence of an external magnetic field breaking time-reversal symmetry. The introduction of such an external perturbation opens up a gap in the phase of the system characterized by non-Abelian statistics. The resulting model belongs to a symmetry-protected class, so that the Uhlmann number can be analyzed. We first consider the Berry curvature on a particular evolution line over the phase diagram. The mean Uhlmann curvature and the Uhlmann number are then analyzed by assuming a thermal state. The mean Uhlmann curvature describes a crossover effect as temperature rises. In the trivial phase, a nonmonotonic dependence of the Uhlmann number, as temperature increases, is reported and explained.
Bascone, F., Leonforte, L., Valenti, D., Spagnolo, B., & Carollo, A. (2019). Finite-temperature geometric properties of the Kitaev honeycomb model. PHYSICAL REVIEW. B, 99(20), 205155-1-205155-10 [10.1103/PhysRevB.99.205155].
Data di pubblicazione: | 2019 | |
Titolo: | Finite-temperature geometric properties of the Kitaev honeycomb model | |
Autori: | ||
Citazione: | Bascone, F., Leonforte, L., Valenti, D., Spagnolo, B., & Carollo, A. (2019). Finite-temperature geometric properties of the Kitaev honeycomb model. PHYSICAL REVIEW. B, 99(20), 205155-1-205155-10 [10.1103/PhysRevB.99.205155]. | |
Rivista: | ||
Digital Object Identifier (DOI): | http://dx.doi.org/10.1103/PhysRevB.99.205155 | |
Abstract: | We study finite-temperature topological properties of the Kitaev’s spin-honeycomb model in the vortex-free sector with the use of the recently introduced mean Uhlmann curvature. We employ an appropriate fermionization procedure to study the system as a two-band p-wave superconductor described by a Bogoliubov–de Gennes Hamiltonian. This allows us to study relevant quantities such as Berry and mean Uhlmann curvatures in a simple setting. More specifically, we consider the spin honeycomb in the presence of an external magnetic field breaking time-reversal symmetry. The introduction of such an external perturbation opens up a gap in the phase of the system characterized by non-Abelian statistics. The resulting model belongs to a symmetry-protected class, so that the Uhlmann number can be analyzed. We first consider the Berry curvature on a particular evolution line over the phase diagram. The mean Uhlmann curvature and the Uhlmann number are then analyzed by assuming a thermal state. The mean Uhlmann curvature describes a crossover effect as temperature rises. In the trivial phase, a nonmonotonic dependence of the Uhlmann number, as temperature increases, is reported and explained. | |
Settore Scientifico Disciplinare: | Settore FIS/03 - Fisica Della Materia | |
Appare nelle tipologie: | 1.01 Articolo in rivista |
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