Related papers: Intrinsic spin Hall effect in topological insulato…
Topological insulators are characterized by a nontrivial band topology driven by the spin-orbit coupling. To fully explore the fundamental science and application of topological insulators, material realization is indispensable. Here we…
This thesis predicts that two types of material families could be a solution to the challenges in spintronics: complex oxides and bismuth based materials. We derive a general approach for constructing an effective spin-orbit Hamiltonian,…
The indirect exchange interaction between local magnetic moments via surface electrons has been long predicted to bolster the surface ferromagnetism in magnetic topological insulators (MTIs), which facilitates the quantum anomalous Hall…
We have investigated spin Hall effects in 4$d$ and 5$d$ transition metals, Nb, Ta, Mo, Pd and Pt, by incorporating the spin absorption method in the lateral spin valve structure; where large spin current preferably relaxes into the…
Three-dimensional topological insulators of finite thickness can show the quantum Hall effect (QHE) at the filling factor $\nu=0$ under an external magnetic field if there is a finite potential difference between the top and bottom…
Topological insulators have been predicted to exhibit a variety of interesting phenomena including a quantized magnetoelectric response and novel spintronics effects due to spin textures on their surfaces. However, experimental observation…
We study theoretically helical edge states of 2D and 3D topological insulators (TI) tunnel-coupled to metal leads and show that their transport properties are strongly affected by contacts as the latter play a role of a heat bath and induce…
The spin Hall effect (SHE) is the conversion of charge current to spin current, and non-magnetic metals with large SHEs are extremely sought after for spintronic applications, but their rarity has stifled widespread use. Here we predict and…
Topological insulators are emerging materials with insulating bulk and symmetry protected nontrivial surface states. One of the most fascinating transport behaviors in a topological insulator is the quantized anomalous Hall insulator, which…
We detected the spin polarization due to charge flow in the spin non-degenerate surface state of a three dimensional topological insulator by means of an all-electrical method. The charge current in the bulk-insulating topological insulator…
Based on a combination of $k \cdot p$ theory, band topology analysis and electronic structure calculations, we predict the (111) thin films of the SnTe class of three-dimensional (3D) topological crystalline insulators realize the quantum…
Spin-based electronics in topological insulators (TIs) is favored by the long spin coherence1,2 and consequently fault-tolerant information storage. Magnetically doped TIs are ferromagnetic up to 13 K,3 well below any practical operating…
The Bi$_2$Se$_3$ class of topological insulators has recently been shown to undergo a superconducting transition upon hole or electron doping (Cu$_x$-Bi$_2$Se$_3$ with T$_C$=3.8$^o$K and Pd$_x$-Bi$_2$Te$_3$ with T$_C$=5$^o$K), raising the…
We describe a new effect in semiconductor spintronics that leads to dissipationless spin-currents in paramagnetic spin-orbit coupled systems. We argue that in a high mobility two-dimensional electron system with substantial Rashba…
We generalize the topological response theory of three-dimensional topological insulators (TI) to metallic systems-specifically, doped TI with finite bulk carrier density and a time-reversal symmetry breaking field near the surface. We show…
Spin Hall effect in metallic Pt is studied with first-principles relativistic band calculations. It is found that intrinsic spin Hall conductivity (SHC) is as large as $\sim 2000 (\hbar/e)(\Omega {\rm cm})^{-1}$ at low temperature, and…
Nontrivial band topology along with magnetism leads to different novel quantum phases. When time-reversal-symmetry is broken in three-dimensional topological insulators (TIs) by applying high enough magnetic field or proximity effect,…
While moir\'e phenomena have been extensively studied in low-carrier-density systems such as graphene and semiconductors, their implications for metallic systems with large Fermi surfaces remain largely unexplored. Using GPU-accelerated…
We complete measurements of interconversions among the full triad of thermal gradients, charge currents, and spin currents in the topological insulator Bi$_2$Se$_3$ by quantifying the efficiency with which thermal gradients can generate…
We study the three-dimensional topological insulator (Bi$_{1-x}$Sb$_{x}$)$_{2}$Te$_{3}$ in its ultrathin limit i.e. when the thickness is of the same order as the surface state penetration depth. It is expected that in this limit a…