Bound states induced by a ferromagnetic delta-layer inserted into a three-dimensional topological insulator
V. N. Men'shov, V. V. Tugushev, E. V. Chulkov+
National Research Centre "Kurchatov Institute", 123182 Moscow, Russia
Tomsk State University, 634050 Tomsk, Russia
+Departamento de Fisica de Materiales, Facultad de Ciencias Quimicas, UPV/EHU and Centro de Fisica de Materiales CFM-MPC, Centro Mixto CSIC-UPV/EHU, Apdo. 1072, 20080 San Sebastián, Basque Country, Spain
Abstract
We report on theoretical study of the bound electron states
induced by a ferromagnetic delta-layer embedded into a narrow-band-gap
semiconductor of the Bi2Se3-type which is a three-dimensional
topological insulator with large spin-orbit coupling. We make use of an
effective Hamiltonian taking into account the inverted band structure of the
semiconductor host at the Γ point and describe the properties of the
in-gap bound states: energy spectrum, characteristic length and spin
polarization. We highlight a role of these states for a magnetic proximity
effect in digital magnetic heterostructures based on the Bi2Se3-type
semiconductors.