ALLOY ANALOG APPROACH AND THE GUTZWILLER APPROXIMATION AS PARTICULAR CASES OF A MEAN-FIELD THEORY
1992 ◽
Vol 06
(20)
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pp. 3341-3352
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Keyword(s):
We develop a new mean field-theory for systems with on-site correlations, like the Hubbard and Anderson models. It consists in a generalization of the saddle-point approximation to the functional integral representation proposed by Kotliar and Ruckenstein to more than one saddle point. It contains also the alloy analog approximation proposed by Hubbard as a particular case. For a half-filled Hubbard model and a model density of states appropriate for three dimensions, we obtain a metal to insulator transition as U increases. The effective Hamiltonian for the insulating phase contains two split bands (rather than only one with an extremely heavy mass) which reproduce correctly the Green’s functions of the atomic limit.
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2004 ◽
Vol 467-470
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pp. 1129-1136
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2007 ◽
Vol 550
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pp. 589-594
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Keyword(s):
Keyword(s):
2007 ◽
pp. 589-594
Keyword(s):
1992 ◽
Vol 25
(18)
◽
pp. 4723-4735
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Keyword(s):
1989 ◽
Vol 03
(12)
◽
pp. 2019-2047
Keyword(s):
1991 ◽
Vol 66
(3)
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pp. 377-380
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