Quantized hole states detected by photoemission in ultrathin epitaxial CoSi2films on Si(111)

Abstract
Angle-resolved photoemission spectra from ultrathin (≤20 Å) epitaxial CoSi2 films on Si(111) reveal narrow features with binding energies in the 0-0.6 eV energy window that depend drastically on film thickness. These peaks reflect quantized hole states arising from particle confinement to a narrow potential well in the direction normal to the surface. Evidence is also presented for significant changes in the CoSi2 crystal potential at very small film thicknesses.