Metal-insulator transition in Au atomic chains on Si with two proximal bands.
One-dimensional atomic chains on Au/Si(557) feature two proximal 1D bands near the Fermi level, which were controversially attributed as a spinon-holon pair of a Luttinger liquid. Angle-resolved photoemission shows that only one band is metallic with the neighboring one gapped at room temperature. Furthermore, even the metallic branch is found to undergo a metal-insulator transition upon cooling, which follows a mean-field-type behavior. Scanning tunneling microscopy observes two apparently unequivocal chains on the surface, one of which exhibits periodicity doubling accompanying the metal-insulator transition. The surface 1D structure is thus concluded to be insulating at low temperature with a Peierls-type instability.
Ahn
J R
JR
Institute of Physics and Applied Physics, Center for Atomic Wires and Layers, Yonsei University, Seoul 120-746, Korea.
Yeom
H W
HW
Yoon
H S
HS
Lyo
I-W
IW