Observation of Spin-Split Electronic States in Solids by Energy-, Angle-, and Spin-Resolved Photoemission

Abstract

The combination of high energy and angle resolution (100 meV, \ifmmode\pm\else\textpm\fi{}3\ifmmode^\circ\else\textdegree\fi{}) with spin analysis in photoemission spectroscopy is shown to allow the direct observation of magnetically spin-split electronic states. This is demonstrated for normal emission from Ni(110) with polarized Ne i radiation ($h\ensuremath{\nu}=16.85$ eV). It is found that ${\ensuremath{\Delta}}_{\mathrm{ex}}=0.18$ eV for the exchange splitting of the ${S}_{4}$ band at the $X$ point in good agreement with a band-structure and photoemission calculation that considers the self-energy correction explicitly.