Drastic change in density of states upon martensitic phase transition for metamagnetic shape memory alloy Ni2Mn(1+x)In(1-x).

We have unravelled the electronic structure of a class of metamagnetic shape memory alloy Ni2Mn1+x In1-x by combining bulk-sensitive hard x-ray photoelectron spectroscopy and first-principles density-functional calculations. A sharp drop in the Ni 3d e(g) density of states forming a pseudogap in the martensitic phase transition (MPT) for x   =   0.36 has been observed near the Fermi level.

Experimental evidence of hidden topological surface states in PbBi4Te7.

A topological surface state that is protected physically under the Bi2Te3-like five-layer block has been revealed on the Pb-based topological insulator (TI) PbBi4Te7 by bulk sensitive angle-resolved photoelectron spectroscopy (ARPES). Furthermore, conservation of the spin polarization of the hidden topological surface states is directly confirmed by bulk-sensitive spin ARPES observation. This finding paves the way to realize the real spintronics devices by TIs that are operable in the real environment.

Perpendicular magnetic anisotropy with enhanced orbital moments of Fe adatoms on a topological surface of Bi2Se3.

We have found a perpendicular magnetic anisotropy of iron adatoms on a surface of the prototypical three-dimensional topological insulator Bi2Se3 by using x-ray magnetic circular dichroism measurements. The orbital magnetic moment of Fe is strongly enhanced at lower coverage, where angle-resolved photoemission spectroscopy shows coexistence of non-trivial topological states at the surface.