Surface electronic structure of Si (111)-(7×7) resolved in real space

We have obtained the first energy-resolved real-space images of the filled and empty surface states of the Si(111)-(7×7) surface, with 3-A lateral resolution. This ability to resolve spatially these surface states with a scanning tunneling microscope depends upon a new method to acquire and separate geometric and electronic information. Our results not only are in good agreement with previous spectroscopic studies but also directly reveal the atomic location and geometric origin of the Si(111)-(7×7) surface states. © 1986 The American Physical Society.