ABSTRACT
A typical condensed-matter crystal consists of a periodic atomic arrangement, in which each atom might have several valence electrons distributed around an ionic core. The high-resolution ARPES is the only experimental instrument able to directly measure the wave-vector dependence of the occupied energy bands. Experimental measurements can directly identify the main characteristics of the essential properties; furthermore, the detailed comparisons with the theoretical predictions will provide the concise physical and chemical pictures to establish the basic concepts. STM is a powerful experimental technique in revealing the spatially atomic distributions with the nanoscale precisions. The very accurate measurements on the carbon-related systems have confirmed the rich and unique geometric structures, illustrating the complex relations among the hexagonal lattice, the finite-size confinement, the flexible feature, and the diverse chemical bondings of carbon atoms. Spin structures and their excitations, with the atomic resolution, play an important role in understanding magnetic properties and spin-dependent phenomena.
