Abstract.
The two-band Hubbard model involving subbands of different widths is investigated via finite-temperature exact diagonalization (ED) and dynamical mean field theory (DMFT). In contrast to the quantum Monte Carlo (QMC) method which at low temperatures includes only Ising-like exchange interactions to avoid sign problems, ED permits a treatment of Hund's exchange and other onsite Coulomb interactions on the same footing. The role of finite-size effects caused by the limited number of bath levels in this scheme is studied by analyzing the low-frequency behavior of the subband self-energies as a function of temperature, and by comparing with numerical renormalization group (NRG) results for a simplified effective model. For half-filled, non-hybridizing bands, the metallic and insulating phases are separated by an intermediate mixed phase with an insulating narrow and a bad-metallic wide subband. The wide band in this phase exhibits different degrees of non-Fermi-liquid behavior, depending on the treatment of exchange interactions. Whereas for complete Hund's coupling, infinite lifetime is found at the Fermi level, in the absence of spin-flip and pair-exchange, this lifetime becomes finite. Excellent agreement is obtained both with new NRG and previous QMC/DMFT calculations. These results suggest that-finite temperature ED/DMFT might be a useful scheme for realistic multi-band materials.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
For a review of early papers, see: A. Georges, G. Kotliar, W. Krauth, M.J. Rozenberg, Rev. Mod. Phys. 68, 13 (1996)
For recent reviews, see: K. Held, e-print arXiv:cond-mat/0511293; A. Georges et al., e-print arXiv:cond-mat/0403123; G. Kotliar, S. Savrasov, e-print arXiv:cond-mat/0208241
J.E. Hirsch, R.M. Fye, Phys. Rev. Lett. 56, 2521 (1986)
For a discussion of this problem, see: K. Held, D. Vollhardt, Eur. Phys. J. B 5, 473 (1998)
R. Arita, K. Held, Phys. Rev. B 96, 201102 (2005); see also: S. Sakai, R. Arita, H. Aoki, Phys. Rev. B 70, 172504 (2004)
A. Koga, N. Kawakami, T.M. Rice, M. Sigrist, Phys. Rev. B 72, 045128 (2005)
See also: A.N. Rubtsov, V.V. Savkin, A.I. Lichtenstein, Phys. Rev. B 72, 035122 (2005)
M. Caffarel, W. Krauth, Phys. Rev. Lett. 72, 1545 (1994)
V.I. Anisimov, I.A. Nekrasov, D.E. Kondakov, T.M. Rice, M. Sigrist, Euro. Phys. J. B 25, 191 (2002)
A. Liebsch, Europhys. Lett. 63, 97 (2003)
A. Liebsch, Phys. Rev. Lett. 91, 226401 (2003)
A. Koga, N. Kawakami, T.M. Rice, M. Sigrist, Phys. Rev. Lett. 92, 216402 (2004)
A. Liebsch, Phys. Rev. B 70, 165103 (2004)
A. Koga, N. Kawakami, T.M. Rice, M. Sigrist, Physica B 359–361, 1366 (2005)
Yun Song, L.-J. Zou, Phys. Rev. B 72, 085114 (2005)
A. Liebsch, Phys. Rev. Lett. 95, 116402 (2005)
K. Inaba, A. Koga, S. Suga, N. Kawakami, J. Phys. Soc. Jpn 74, 2393 (2005)
L. de' Medici, A. Georges, S. Biermann, Phys. Rev. B 72, 205124 (2005)
M. Ferrero, F. Becca, M. Fabrizio, M. Capone, Phys. Rev. B 72, 205126 (2006).
C. Knecht, N. Blümer, P.G.J. van Dongen, Phys. Rev. B 72, 081103(R) (2005)
S. Biermann, L. de' Medici, A. Georges, Phys. Rev. Lett. 95, 206401 (2005)
J. Jaklič, P. Prelovšek, Adv. Phys. 49, 1 (2000)
M. Capone, L. de' Medici, A. Georges, e-print arXiv:cond-mat/0512484
T. Maeno, T.M. Rice, M. Sigrist, Phys. Today 54, 42 (2001)
K. Takada et al., Nature 422, 53 (2003); R.E. Schaak et al., Nature 424, 527 (2003); M.L. Foo et al., Phys. Rev. Lett. 92, 247001 (2004)
Th. Pruschke, R. Bulla, Eur. Phys. J. B 44, 217 (2005)
T.A. Costi, N. Manini, J. Low Temp. Phys. 126, 835 (2002)
K.G. Wilson, Rev. Mod. Phys. 47, 773 (1975)
T.A. Costi, A.C. Hewson, V. Zlatic, J. Phys.: Condens. Matter 6, 2519 (1994)
W. Hofstetter, Phys. Rev. Lett. 85, 1508 (2000)
D.M. Cragg, P. Lloyd, J. Phys. C: Solid State Phys. 12, L215 (1979).
W. Koller, A.C. Hewson, D. Meyer, Phys. Rev. B 72, 045117 (2005)
R. Bulla, T. Pruschke, A.C. Hewson, J. Phys.: Condens. Matter 10, 8365 (1998)
R. Bulla, T.A. Costi, D. Vollhardt, Phys. Rev. B 64, 045103 (2001)
T.A. Costi, to be published
A. Liebsch, to be published
H. Kajueter, G. Kotliar, Phys. Rev. Lett. 77, 131 (1997)
A. Georges, G. Kotliar, Phys. Rev. B 45, 6479 (1992)
A.I. Lichtenstein, M.I. Katsnelson, Phys. Rev. B 57, 6884 (1998)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Liebsch, A., Costi, T. Non-Fermi-liquid phases in the two-band Hubbard model: finite-temperature exact diagonalization study of Hund's rule coupling. Eur. Phys. J. B 51, 523–536 (2006). https://doi.org/10.1140/epjb/e2006-00248-0
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1140/epjb/e2006-00248-0