Work performed within the research program of the Sonderforschungsbereich 341, Köln-Aachen-Jülich.
- Autor(in)
- Referenz
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10 A. Mielke, J. Phys. A24 (1991) L73;
11 H. Tasaki, Phys. Rev. Lett. 69 (1992) 1608
12 B. S. Shastry, H. R. Krishnamurthy, P. W. Anderson, Phys. Rev. B41 (1990) 2375
13 P. Fazekas, B. Menge, E. Müller-Hartmann, Z. Phys. B - Condensed Matter 78 (1990) 69
14 A. G. Basile, V. Elser, Phys. Rev. B41 (1990) 4842
15 W. von der Linden, D. M. Edwards, J. Phys. Cond. Matter 3 (1991) 4917
16 F. Gebhard, X. Zotos, Phys. Rev. B43 (1991) 1176
17 H. Yokoyama, H. Shiba, J. Phys. Soc. Japan 56 (1987) 3570
18 P. Richmond, G. Rickayzen, J. Phys. C2 (1969) 528
19 P. B. Visscher, Phys. Rev. B 10 (1974) 943
1 M. C. Gutzwiller, Phys. Rev. Lett. 10 (1963) 159
20 D. Vollhardt, Rev. Mod. Phys. 56 (1984) 99
21 Th. Hanisch, Diploma Thesis, University of Cologne 1992
22 W. F. Brinkman, T. M. Rice, Phys. Rev. B2 (1970) 4302
23 E. Müller-Hartmann, Th. Hanisch, R. Hirsch, SCES 1992, Sendai, Japan 1992
24 R. Hirsch, E. Müller-Hartmann, to be published
25 W. O. Putikka, M. U. Luchini, M. Ogata, Phys. Rev. Lett. 69 (1992) 2288
26 For the definitions of the complete elliptic integrals and many useful identities, in: Handbook of Mathematical Functions, M. Abramovitz, I. A. Stegun (eds.), NBS, Washington 1966
27 T. Morita, J. Math. Phys. 12 (1971) 1744
2 J. Hubbard, Proc. R. Soc. London A276 (1963) 238
3 J. Kanamori, Prog. Theor. Phys. 30 (1963) 275
4 Y. Nagaoka, Phys. Rev. 147 (1966) 392
5 D. C. Mattis, The Theory of Magnetism I, Springer Series in Solid State Science 17, Springer, Berlin-Heidelberg-New York 1981
6 M. Takahashi, J. Phys. Soc. Japan 51 (1982) 3475
7 Y. Fang, A. E. Ruckenstein, E. Dagotto, S. Schmitt-Rink, Phys. Rev. B40 (1989) 7406
8 K. Hashimoto, J. Phys. Soc. Japan 54 (1985) 33
9 A. Barbieri, J. A. Riera, A. P. Young, Phys. Rev. B41 (1990) 11697
J. Phys. A24 (1991) 3311;
J. Phys. A25 (1992) 4335
- Seitenbereich
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0381 - 0397
- Schlagwort(e)
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<KWD>Hubbard model
Correlated electrons
Ferromagnetism
- Zusammenfsg.
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The instability of the fully polarized ferromagnetic ground state (Nagaoka state) of the Hubbard model on the square lattice is investigated. We use single spin flip variational wave functions including majority spin correlation effects and calculate spin flip energies in the thermodynamic limit. With very local wave functions and with moderate numbers of variational parameters we reproduce the best known estimate for the critical hole density <I>δ<sub>cr</sub></I> = 0.29 and we obtain an estimate of <I>U</I><sub><I>cr</I></sub> = 63 <I>t</I> for the critical coupling which is considerably better than the best estimate of <I>U</I><sub><I>cr</I></sub> = 42 <I>t</I> previously known. The simplicity of our wave functions makes the physical origin of the various aspects of the instability particularly transparent.
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- Forschungsartikel