2005 Volume 74 Issue 2 Pages 208-212
The ground state of Si(001) reconstructed surface at low temperatures had not been determined by 2003. Since 2000, when the (2x1) phase composed of symmetric dimers or symmetrically appearing dimers was proposed as the most stable phase below 20 K, a significant amount of experimental and theoretical research has been continuously performed on this issue. In determining the true ground state of Si(001) surface by low-temperature scanning tunneling microscopy (STM), we discovered that asymmetric dimer phases, c(4x2) and p(2x2), are much more stable than p(2x1). Moreover, we discovered that the surface reconstruction phase can be controlled between the two asymmetric phases reversibly by STM. Thus, we conclude that c(4x2) is the ground state. In this article, we review the research studies on Si(001) surfaces and the present understanding of the STM manipulation of asymmetric dimer phases.
