Effect of surface hybridization on RKKY coupling in ferromagnet/topological insulator/ferromagnet trilayer system
arXiv:1611.06710 · doi:10.1063/1.4977072
Abstract
We theoretically investigate the RKKY exchange coupling between two ferromagnets (FM) separated by a thin topological insulator film (TI). We find an unusual dependence of the RKKY exchange coupling on the TI thickness (). First, when decreases, the coupling amplitude increases at first and reaches its maximum value at some critical thickness, below which the amplitude turns to diminish. This trend is attributed to the hybridization between surfaces of the TI film, which opens a gap below critical thickness and thus turns the surfaces into insulating state from semi-metal state. In insulating phase, diamagnetism induced by the gap-opening compensates paramagnetism of Dirac state, resulting in a diminishing magnetic susceptibility and RKKY coupling. For typical parameters, the critical thickness in Bi2Se3 thin film is estimated to be in the range of 3-5 nm.
arXiv comment4 pages, 3 figures, MMM conference 2016, updated bib. in AIP Advances (2017)
References in corpus (17)
- Quantum Spin Hall Effect in Graphene
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
- Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
- Spin Transfer Torque Generated by the Topological Insulator Bi_2Se_3
- Aharonov-Bohm interference in topological insulator nanoribbons
- Massive Dirac fermions and spin physics in an ultrathin film of topological insulator
- Magnetic impurities on the surface of a topological insulator
- Oscillatory crossover from two dimensional to three dimensional topological insulators
- Inverse Spin-Galvanic Effect in a Topological-Insulator/Ferromagnet Interface
- Spin Hall effect transistor
- Massive Dirac surface states in topological insulator/magnetic insulator heterostructures
- High-Temperature Quantum Anomalous Hall Effect in n-p Codoped Topological Insulators
- Parallel magnetic field driven quantum phase transition in a thin topological insulator film
- Electrically Tunable Magnetism in Magnetic Topological Insulators
- Spin-injection Hall effect in a planar photovoltaic cell
- Magnetic Proximity Effect and Interlayer Exchange Coupling of Ferromagnetic/Topological Insulator/Ferromagnetic Trilayer