Kosterlitz-Thouless Transition: The Diluted XY model

7th Brazilian Meeting on Simulational Physics

Costa, B.V.^1 ; Lima, L.S.^1 ; Coura, P.Z.^2 ; Leonel, S.A.^2 ; Lima, A.B.^3

Department of Physics, Universidade Federal de Minas Gerais, Brazil^1

Department of Physics, Universidade Federal de Juiz de Fora, Brazil^2

Department of Physics, Universidade Federal Do Triangulo Mineiro, Brazil^3

关键词: Anomalous behavior;    Berezinskii-Kosterlitz-Thouless transition;    Classic models;    Different sizes;    Kosterlitz-Thouless transitions;    Quantum fluctuation;    Square lattices;    Vacancy density;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/487/1/012008/pdf
DOI  :  10.1088/1742-6596/487/1/012008

来源: IOP

【 摘 要 】

The effect of nonmagnetic disorder on Berezinskii-Kosterlitz-Thouless (BKT) transition in the two-dimensional ferromagnetic XY model on a square lattice, diluted by randomly placed vacancies can be an important source of information on the role played by vortexes in this transition. The transition temperature TBKTis determined as a function of vacancy density ρvby stiffness ρ and for different size of the lattice. The anomalous behavior for TBKTwhen ρvis close to the square lattice percolation limit is a consequence of the effect of finite size of lattice and not due the quantum fluctuations as concluded in literature. We obtain that TBKTfalls to zero at ρv0.40 close to the value 0.41 obtained for the classic model.