Dresden 2003 – wissenschaftliches Programm

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O: Oberflächenphysik

O 4: Elektronische Struktur I

O 4.1: Vortrag

Montag, 24. März 2003, 11:15–11:30, FOE/ANOR

Superlattice effects in angle-resolved photoemission from stepped W(331) — •A. Varykhalov¹, A. M. Shikin^1,2, G. V. Prudnikova², V. Mojaiskii², W. Gudat¹, and O. Rader¹ — ¹BESSY Berlin — ²St. Petersburg State University

Umklapp transitions are an important concept leading to strong effects on angle-resolved photoemission spectra [1]. It can be expected that introduction of a superlattice of regular steps on a vicinal surface leads to substantial deviations from data obtained from the corresponding flat surface. These should be measurable for k-vectors perpendicular to the step edges while in the parallel direction data should resemble the one measured on flat surfaces. We compare W(331) with W(110) along the in-plane Γ-H direction and find clear differences in the angle dispersion comparing the two surfaces and, in particular, between two valence-band features on the same W(331) sample, one of which is explained based on umklapp processes caused by the superlattice geometry.

[1] See, e. g., C. Westphal and A. Goldmann, Surf. Sci. 126, 253 (1983).