Electronic structure of one-dimensional indium chains on Si(111)

The driving force for the phase transition of quasi-one-dimensional (1D) indium chains on the Si(Ill)-4 X 1 surface has been controversial. Using first-principles density-functional calculations we investigate the surface band structure of the low-temperature phase including a periodic lattice distortion. We find that the surface states m(2) and m(3) hybridize to yield a band-gap opening, while the surface state in, crosses the Fermi level. The simulated scanning tunneling microscopy (STM) images reproduce the features observed in the STM measurements, such as a double periodicity and an out-of-phase distribution in the filled- and empty-state images. The present results agree in many respects with recent photoelectron spectroscopy and STM experiments but do not support a 1D charge-density-wave mechanism accompanying a metal-insulator transition.