The "ultimate" scanning tunneling microscopy images of the Si(111)-(7×7) surfaces

Both the 12 adatoms and the 6 rest atoms of the Si(111)-(7×7) unit cell are obtained clearly with the highest resolution to date using ultrahigh vacuum scanning tunneling microscopy (STM). It is found that the 6 rest atoms have the same brightness as the center adatoms in the unfaulted half unit of the Si(111)-(7×7). The very sharp tip of less than 7 can clearly resolve the rest atoms. The total-energy calculated from first-principles is in remarkable agreement with the experimental results.