Identification of single-layer metallic structure of indium on Si(1 1 1)

We have studied the In/Si(1 1 1) ()-hex and striped phases by low-energy electron diffraction (LEED) and angle-resolved photoelectron spectroscopy (ARPES). The two phases are formed by different processes, and hence the different names have been used conventionally. We, however, found that LEED I– curves of the two phases agree with each other, indicating that they have an identical atomic structure. Our ARPES measurement revealed that the ()-hex phase has metallic surface states. The observed Fermi surface was found to be very similar to the theoretical one calculated for an indium single-layer model. (paper)