Fermi gap stabilization of an incommensurate two-dimensional superstructure

Physical Review Letters 94, 16103 - 4 (2005)

Fermi gap stabilization of an incommensurate two-dimensional superstructure

F. Schiller, J. Cordón, D. Vyalikh, A. Rubio, J. E. Ortega

The compressed, incommensurate (9.5 9.5) Moire superstructure of the Ag monolayer on Cu(111) displays a lled surface state band with a Fermi energy gap at the Brillouin zone boundary. By contrast, the surface band is gapless for the less compressed, conmensurate (9 9) Moire of two Ag layers. A simple estimate of the energy gain rendered by opening this gap gives a value compatible with the elastic energy change required to modify commensurate structures, thereby suggesting that the (9.5 9.5) incommensurate phase is stabilized by such gap opening. The possible presence of a charge density wave state is discussed.

Additional Information

Download
Preprint - 177 KB
Doi
http://dx.doi.org/10.1103/PhysRevLett.94.016103

Related Research Areas