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Various reconstruction phases on SiC surfaces exhibit strong Coulomb interaction between dangling bonds leading to electron correlation effects. Such effects might be pushed forward towards low-dimensional surface electron systems, if strongly anisotropic atomic arrangements can be achieved. A promising candidate in this respect is the 4H-SiC(1-102) surface, since already in bulk-truncated geometry it consists of alternating stripes of different bond configuration with a nanometer periodicity. The present study takes on a detailed investigation of the electronic and atomic properties of this surface using low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), X-ray and ultra-violet photoelectron spectroscopy (XPS and UPS). Two well ordered reconstruction phases can be prepared by annealing under simultaneous Si-flux. The surface forms a Si rich (2x1) and a nearly stoichiometric c(2x2) structure. From STM the surface seems to contain single adatoms per unit cell in both phases, which in particular for the (2x1) phase are located on top of a Si adlayer (3Å thick), and appear to form isolated atomic rows in separation of the (2x1) unit cell size. This phase displays a prominent surface state in the gap as revealed by UPS. The surface state shows dispersion only in the direction of the atomic rows with a bandwidth of 0.2 eV. Apparently, this electronic state is delocalized along the nanowires and obviously represents a one-dimensionally confined electron system. Detailed studies of the electronic and atomic structure of both the (2x1) and the c(2x2) phase will be presented and discussed. |