Electronic stabilization of a 5 × 4 dopant superlattice on Si ( 111 ) 5 × 2 − Au

The $\mathrm{Si}(111)5\ifmmode\times\else\texttimes\fi{}2\text{\ensuremath{-}}\mathrm{Au}$ surface exhibits a chain structure with additional Si atoms on top of the chains. They dope the chains to achieve the optimum band filling, according to recent local density calculations. Surprisingly, the Si atoms form a half-filled, disordered $5\ifmmode\times\else\texttimes\fi{}4$ lattice fluid, not an ordered $5\ifmmode\times\else\texttimes\fi{}8$ lattice. From their autocorrelation function an interatomic potential with $5\ifmmode\times\else\texttimes\fi{}4$ periodicity was deduced. An explanation for the $5\ifmmode\times\else\texttimes\fi{}4$ periodicity is provided by establishing a connection to the electronic structure near the Fermi level ${E}_{F}$, which is mapped by angle-resolved photoemission. The constant energy surfaces near ${E}_{F}$ consist of one-dimensional lines at the boundaries of a $5\ifmmode\times\else\texttimes\fi{}4$ Brillouin zone. Such nested features of high density of states are capable of triggering a $5\ifmmode\times\else\texttimes\fi{}4$ superlattice interaction. The measurements establish a two-way connection between electronic structure and interatomic potentials: A one-dimensional Fermi surface instability triggers a superlattice of extra atoms, and the atoms provide the correct number of electrons for such an instability to occur. The band structure is discussed in view of the recently observed phase-separation into nanometer-sized segments of metallic and semiconducting character.

[1]  J. Crain,et al.  Chains of gold atoms with tailored electronic states , 2004 .

[2]  C. Whang,et al.  Novel electronic structure of inhomogeneous quantum wires on a Si surface. , 2004, Physical review letters.

[3]  T. Greber,et al.  Reinvestigation of the band structure of the Si ( 111 ) 5 × 2 -Au surface , 2003 .

[4]  I. Lyo,et al.  Metal-insulator transition in Au atomic chains on Si with two proximal bands. , 2003, Physical review letters.

[5]  S. Erwin.  Self-doping of gold chains on silicon: a new structural model for Si(111)-(5 x 2)-Au. , 2003, Physical review letters.

[6]  J. Crain,et al.  Silicon adatoms on the Si(1 1 1)5 × 2-Au surface , 2003 .

[7]  M. Kang,et al.  Theoretical investigation of the Au/Si(1 1 1)-(5 × 2) surface structure , 2003 .

[8]  J. Crain,et al.  Fractional band filling in an atomic chain structure. , 2003, Physical review letters.

[9]  F. Himpsel,et al.  Correlations in a one-dimensional lattice fluid on Si(111)5×2-Au , 2003 .

[10]  R. Uhrberg,et al.  Surface electronic structure study of Au/Si(111) reconstructions : Observation of a crystal-to-glass transition , 2002 .

[11]  J. Crain,et al.  Photoelectron spectroscopy of atomic wires , 2002 .

[12]  T. Aruga.  Charge-density waves on metal surfaces , 2002 .

[13]  R. Martin,et al.  First principles study of the Si(557)-Au surface , 2002, cond-mat/0208134.

[14]  H Germany,et al.  Fermi Surfaces of Surface States on Si(111) , 2002, cond-mat/0205005.

[15]  J. Crain,et al.  Atomic scale memory at a silicon surface , 2002, cond-mat/0204251.

[16]  Yi Luo,et al.  Identifying isomers of C-78 by means of x-ray spectroscopy , 2002 .

[17]  R. Martin,et al.  Two distinct metallic bands associated with monatomic Au wires on the Si(557)-Au surface , 2001, cond-mat/0105400.

[18]  I. Robinson,et al.  Structure of quantum wires in Au/Si(557). , 2002, Physical review letters.

[19]  J. Crain,et al.  One-dimensional electronic states at surfaces , 2001 .

[20]  J. Crain,et al.  Electronic structure of atomic chains on vicinal SiÑ111Ö-Au , 2001 .

[21]  F. Himpsel,et al.  Band splitting for Si(557)-Au: is it spin-charge separation? , 2001, Physical review letters.

[22]  S. Hasegawa.  REVIEW ARTICLE: Surface-state bands on silicon as electron systems in reduced dimensions at atomic scales , 2000 .

[23]  Himpsel,et al.  Continuous transition from two- to one-dimensional states in Si(111)-( 5x2)-Au , 2000, Physical review letters.

[24]  F. Himpsel,et al.  Fermi surface of Si ( 111 ) 7 × 7 , 2000 .

[25]  P. Segovia,et al.  Observation of spin and charge collective modes in one-dimensional metallic chains , 1999, Nature.

[26]  F. Himpsel,et al.  Regular step arrays on silicon , 1998 .

[27]  Y. Tezuka,et al.  Surface electronic structure of ordered alkali- and noble metal-overlayers on Si(111) , 1997 .

[28]  R. Venkatesh,et al.  Elastic and other associated properties of C 60 , 1997 .

[29]  S. Suga,et al.  Surface core level shifts of the Au adsorbed Si(111) reconstructed surfaces , 1996 .

[30]  J. McGilp,et al.  Erratum to “Angle-resolved photoemission from an unusual quasi-one-dimensional metallic system: a single domain Au-induced 5 × 2 reconstruction of Si(111)” [Surface Science 325 (1995) 45] , 1995 .

[31]  E. Bauer.  Surface science lettersThe Si(111)−(5 × 1) Au structure , 1991 .

[32]  J. Sólyom.  The Fermi gas model of one-dimensional conductors , 1979 .