Kidd TE, Miller T, Chou MY, Chiang T
Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080 and and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 South Goodwi.
Phys Rev Lett. 2000 Oct 23;85(17):3684-7. doi: 10.1103/PhysRevLett.85.3684.
Angle-resolved photoemission has been utilized to study the surface electronic structure of 1 / 3 monolayer of Sn on Ge(111) in both the room-temperature (sqrt[3]xsqrt[3] )R30 degrees phase and the low-temperature ( 3x3) charge-density-wave phase. The results reveal a gap opening around the ( 3x3) Brillouin zone boundary, suggesting a Peierls-like transition despite the well-documented lack of Fermi nesting. A highly sensitive electronic response to doping by intrinsic surface defects is the cause for this unusual behavior, and a detailed calculation illustrates the origin of the ( 3x3) symmetry.
角分辨光电子能谱已被用于研究室温下（(\sqrt{3}\times\sqrt{3})）(R30^{\circ})相和低温下（(3\times3)）电荷密度波相的(Ge(111))上(1/3)单层(Sn)的表面电子结构。结果揭示了在（(3\times3)）布里渊区边界附近出现能隙，这表明尽管有充分记录表明缺乏费米面嵌套，但仍存在类皮尔斯转变。对本征表面缺陷掺杂的高度敏感电子响应是这种异常行为的原因，详细计算阐明了（(3\times3)）对称性的起源。
