Topologically Entangled Rashba-Split Shockley States on the Surface of Grey Arsenic
Topologically Entangled Rashba-Split Shockley States on the Surface of Grey Arsenic
We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and …