Enhanced and stable spin Hall conductivity in a disordered time-reversal and inversion symmetry broken topological insulator thin film

Abstract

We consider a disordered topological insulator thin film placed on the top of a ferromagnetic insulator with a perpendicular exchange field $M$ and subjected to a perpendicular electric field. The presence of ferromagnetic insulator causes that bottom surface states of the topological insulator thin film become spin polarized and the electric field provides a potential difference $V$ between the two surface states, resulting in breaking of time-reversal and inversion symmetry in the system. Using Kubo formalism and employing the first Born approximation as well as the self-consistent Born approximation, we calculate the spin Hall conductivity. We find that for small values of $V$, a large spin conductivity can be generated through large values of $M$ away from the charge neutrality point. But for large values of $V$, the spin conductivity can be promoted even with small values of $M$ around the charge neutrality point. The effect of vertex corrections and the stability of the obtained large spin conductivity against disorders are also examined.

15 pages, 10 figures

References in corpus (11)

• Classification of topological insulators and superconductors in three spatial dimensions
• Topological Defects and Gapless Modes in Insulators and Superconductors
• Electron transport in disordered graphene
• Anomalous Hall effect in 2D Dirac band: link between Kubo-Streda formula and semiclassical Boltzmann equation approach
• Charge and spin Hall conductivity in metallic graphene
• Large-gap magnetic topological heterostructure formed by subsurface incorporation of a ferromagnetic layer
• Magnetic proximity effect at Bi${}_2$Se${}_3$/EuS interface with broken inversion symmetry
• Streda-like formula in spin Hall effect
• Coherent Oscillations and Giant Edge Magnetoresistance in Singly Connected Topological Insulators
• Disorder effects in topological insulator thin films
• Highly Tunable Spin-Orbit Torque and Anisotropic Magnetoresistance in a Topological Insulator Thin Film Attached to Ferromagnetic Layer

Cited by in corpus (3)

• Electron-electron interactions in partially mixed helical states
• Promoted current-induced spin polarization in inversion symmetry broken topological insulator thin films
• Spin responses of a disordered helical superconducting edge under Zeeman field