title: Effects of the Rashba spin-orbit coupling on Hofstadter's butterfly.
abstract: We study the effect of Rashba spin-orbit coupling on the Hofstadter spectrum of a two-dimensional tight-binding electron system in a perpendicular magnetic field. We obtain the generalized coupled Harper spin-dependent equations which include the Rashba spin-orbit interaction and solve for the energy spectrum and spin polarization. We investigate the effect of spin-orbit coupling on the fractal energy spectrum and the spin polarization for some characteristic states as a function of the magnetic flux α and the spin-orbit coupling parameter. We characterize the complexity of the fractal geometry of the spin-dependent Hofstadter butterfly with the correlation dimension and show that it grows quadratically with the amplitude of the spin-orbit coupling. We study some ground state properties and the spin polarization shows a fractal-like behavior as a function of α, which is demonstrated with the exponent close to unity of the decaying power spectrum of the spin polarization. Some degree of spin localization or distribution around +1 or -1, for small spin-orbit coupling, is found with the determination of the entropy function as a function of the spin-orbit coupling. The excited states show a more extended (uniform) distribution of spin states.
authors.affiliation: Posgrado de Ciencias Fisicas, Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, A Postal 356, Ensenada, Baja, California, 22835, Mexico. sukey@cnyn.unam.mx
authors.forename: S
authors.initials: S
authors.lastname: Sosa y Silva
authors.forename: F
authors.initials: F
authors.lastname: Rojas
mesh_terms: D000465:Algorithms; D004563:Electrochemistry; D004583:Electrons; D008280:Magnetics; D015233:Models, Statistical; D013113:Spin Labels
chemical_list: D013113:Spin Labels