Figure 1: Charge density oscillations induced around an impurity on thin Fe films on W(001).
From: Quantum well states and amplified spin-dependent Friedel oscillations in thin films
(a) STM tip scanning the Fe film surface where the oxygen impurity is implanted. The Fe film is grown on the (001) surface of W. (b) Measured charge density of states (dI/dU map) using a W-tip at the vicinity of the Fermi energy (U=−0.1 eV) induced by an oxygen impurity on three MLs Fe/W(001) (ref. 25) where the bright (dark) colour stands for charge density accumulation (depletion). Comparison with the spin-resolved theoretical charge density oscillations for states at the Fermi energy emanating from an oxygen impurity for two film thicknesses: two and three MLs for the majority-spin channel (c) and (d) followed by the corresponding ones for the minority-spin channel (e) and (f). The square in d encompasses the region probed experimentally and the black spots are obtained after an uppercut of the theoretical data.
