Banca de DEFESA: CAIO VITOR DE SOUZA SOARES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CAIO VITOR DE SOUZA SOARES
DATE: 24/04/2025
TIME: 14:00
LOCAL: Plataforma Google Meet
TITLE:

Visons in Kitaev Spin Liquids with Majorana Fermi Surfaces

KEY WORDS:

Kitaev model, Green’s functions, Lattice scattering, Kagome lattice, Fermi surface, Visons.

PAGES: 62
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

The Kitaev honeycomb model is an exactly solvable model that has a spin liquid ground state. It can have gapped or gapless
excitations from Majorana fermions and vortices of a Z2 gauge field, also known as visons, which are always gapped. The
energy to create a pair of visons has always been calculated numerically in finite-size lattices, but recently, an analytical
expression valid in the thermodynamic limit was derived using Green’s function methods. An analytical method might be
interesting for, when the Majoranas dispersion is gapless, the finite-size effects are stronger and might spoil extrapolations of
the numerical vison gaps to the thermodynamic limit. In this work, we compare both methods to calculate the vison gap in the
Kitaev model and generalize them to another model of spins 3/2 in the kagome lattice, in which Majorana fermions form a
Fermi surface. We find a regime in which the vison gap decreases with the size of the Fermi surface.

 

COMMITTEE MEMBERS:
Externo à Instituição - ERIC DE CASTRO E ANDRADE - USP
Presidente - 1313663 - RODRIGO GONCALVES PEREIRA
Externo à Instituição - THEREZA CRISTINA DE LACERDA PAIVA - UFRJ