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  • Decorative imageProf. Chung-Yu Mou, Prof. Chung-Hou Chung (TG8) and collaborators published their research in Phys. Rev. Lett. on April 29, 2016 on theoretical realization of fermionic finite-temperature Dirac points as critical points separating two topological phases in a Kondo lattice. The underlying Dirac point is central to the profound physics manifested in a wide class of materials. However, it is often difficult to drive a system with Dirac points across the massless fermionic critical point. Here by exploiting screening of local moments under spin-orbit interactions in a Kondo lattice, they show that below the Kondo temperature, the Kondo lattice undergoes a topological transition from a strong topological insulator (STI) to a weak topological insulator (WTI) at a finite temperature TD. At&n...Read More
  • Decorative imageThe study of the spin Hall effect in graphene is an active field of research, but its experimental realization is proven to be difficult due to the inherently weak intrinsic spin-orbit interaction. Thus, one needs to rely on extrinsic spin-orbit scattering to be able to probe this effect in graphene. Prof. Miguel Cazalilla (Distinguished Center Scientist of NCTS and professor in NTHU) and his students/collaborators have reported some progress in this direction. They predict that adatoms on graphene can induce an anisotropic Rashba spin-orbit coupling, and the degree of anisotropy has a noticeable effect on the energy dependence of the spin Hall angle. They study the effect of anisotropy of the Rashba coupling on the extrinsic spin Hall effect due to spin-orbit active adatoms on gr...Read More
  • Decorative imageMagneto-optical Kerr effect, discovered by J. Kerr in 1877, refers to the fact that when a linear polarized light beam hits a magnetic material the polarization plane of the reflected light beams rotates. Nowadays Magneto-optical Kerr effect is widely used as a powerful probe of the electronic and magnetic properties of materials, such as domain wall, surface plasma resonance, magnetic anisotropy and topological insulator.  However, magneto-optical Kerr effect has been found only in magnetic materials with nonzero magnetization such asferromagnets and ferrimagnets. Using first-principles density functional theory, Guang-Yu Guo (a DCS of the NCTS) and his co-workers [1] recently demonstrate for the first time large magneto-optical Kerr effect in high-temperature noncollinearantiferroma...Read More
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