Anisotropic metal-insulator transition in epitaxial thin films.
By comparing the properties of In and Pb quantum wells in a scanning tunneling microscopy subsurface imaging experiment, we found the existence of lateral bound states, a 2D Mott-Hubbard correlation gap, induced by transverse confinement. Its formation is attributed to spin or charge overscreening of quasi-2D excitations. The signature of the 2D confinement-deconfinement transition is also experimentally observed, with the correlation gap being pinned in the middle of the conduction band. A self-organized 2D Anderson lattice is suggested as a new ground state.
Altfeder
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IB
Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Liang
X
X
Yamada
T
T
Chen
D M
DM
Narayanamurti
V
V