Induced spin texture in semiconductor/topological insulator heterostructures

We show that a semiconductor thin film can acquire a non-trivial spin texture due to the proximity effect induced by a topological insulator. The effect stems from coupling to the topological surface states and is present even when the insulator is doped. We propose a semiconductor/topological insulator heterostructure as a device that allows measuring interface properties and probing surface states in uncompensated samples. We also find that the topological insulator surface modes can be significantly broadened and shifted by the presence of metallic contacts.Comment: 6 pages, 2 figures, published versio

Van der Waals Heterostructures Based on Allotropes of Phosphorene and MoSe2

The van der Waals heterostructures of allotropes of phosphorene (${\alpha}$- and $\beta-P$) with MoSe2 (H-, T-, ZT- and SO-MoSe2) are investigated in the framework of state-of-the-art density functional theory. The semiconducting heterostructures, $\beta$-P /H-MoSe2 and ${\alpha}$-P / H-MoSe2, forms anti-type structures with type I and type II band alignments, respectively, whose bands are tunable with external electric field. ${\alpha}$-P / ZT-MoSe2 and ${\alpha}$-P / SO-MoSe2 form ohmic semiconductor-metal contacts while Schottky barrier in $\beta$-P / T-MoSe2 can be reduced to zero by external electric field to form ohmic contact which is useful to realize high-performance devices. Simulated STM images of given heterostructures reveal that ${\alpha}$-P can be used as a capping layer to differentiate between various allotropes of underlying MoSe2. The dielectric response of considered heterostructures is highly anisotropic in terms of lateral and vertical polarization. The tunable electronic and dielectric response of van der Waals phosphorene/MoSe2 heterostructure may find potentials applications in the fabrication of optoelectronic devices.Comment: 27 pages, 7 figures, 1 tabl