Fermi surface of Si ( 111 ) 7 × 7
2000; American Physical Society; Volume: 61; Issue: 16 Linguagem: Inglês
10.1103/physrevb.61.10845
ISSN1095-3795
AutoresR. Losio, K. N. Altmann, F. J. Himpsel,
Tópico(s)Silicon Carbide Semiconductor Technologies
ResumoSurface states at the $\mathrm{Si}(111)7\ifmmode\times\else\texttimes\fi{}7$ surface are mapped by angle-resolved photoemission with $E,\ensuremath{\vartheta}$ multidetection. The adatom states near the Fermi level form a well-defined, two-dimensional energy surface consisting of closed loops that nearly fill the $7\ifmmode\times\else\texttimes\fi{}7$ unit cells. The width of the occupied adatom bands is 0.28 eV, twice as large as predicted by local density theory. Of the 49 possible locations inside the $1\ifmmode\times\else\texttimes\fi{}1$ cell, the loops centered at ${\overline{\ensuremath{\Gamma}}}_{7\ifmmode\times\else\texttimes\fi{}7}=(2/7,0)$ and ${\overline{\ensuremath{\Gamma}}}_{7\ifmmode\times\else\texttimes\fi{}7}=(3/7,\ensuremath{-}1/7)$ dominate in intensity, whereas those near (0,0) are suppressed by more than a factor of 20. These results provide quantitative input for characterizing narrow bands with substantial correlation effects at surfaces with large-scale reconstructions.
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