Electronic structures and photoemission spectroscopy

Abstract:

The combination of topological properties and magnetic order can lead to new quantum states and exotic physical phenomena. In particular, the coupling between topological insulators and antiferromagnets enables magnetic and electronic structural engineering.

Abstract:

An extreme magnetoresistance (XMR) has recently been observed in several nonmagnetic semimetals. Increasing experimental and theoretical evidence indicates that the XMR can be driven by either topological protection or electron-hole compensation. Here, by investigating the electronic structure of a XMR material, YSb, we present spectroscopic evidence for a special case which lacks topological protection and perfect electron-hole compensation. Further investigations reveal that a cooperative action of a substantial difference between electron and hole mobility and a moderate carrier compensation might contribute to the XMR in YSb.

Abstract:

Wafer-sized single-crystalline Cu (100) surface can be readily achieved on stacked polycrystalline Cu foils via simple oxygen chemisorption-induced reconstruction, enabling fast growth of large-scale millimeter-sized single-crystalline graphene arrays under molecular flow. The maximum growth rate can reach 300 μm min^-1 , several orders of magnitude higher than previously reported values for millimeter-sized single-crystalline graphene growth on Cu foils.