d-Mott phases in one and two dimensions.
We use exact diagonalization to determine the spectrum of reduced Hamiltonians based on renormalization group flows to strong coupling. For the half-filled two-leg Hubbard ladder we reproduce the known insulating d-Mott ground state with spin and charge gaps. For the saddle point regions of the two-dimensional Hubbard model near half filling we find a crossover to a similar strong coupling state, which truncates the Fermi surface near the saddle points. At lower scales d-wave superconductivity appears on the remaining Fermi surface.
Läuchli
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A
Laboratoire de Physique Théorique, CNRS-UMR 5152, Université Paul Sabatier, F-31062 Toulouse, France.
Honerkamp
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C
Rice
T M
TM