1 / 16

Challenges in Strongly Correlated Electron Systems: A Dynamical Mean Field Theory Perspective

Challenges in Strongly Correlated Electron Systems: A Dynamical Mean Field Theory Perspective. Gabriel Kotliar and Center for Materials Theory & CPHT Ecole Polytechnique Palaiseau & SPHT CEA Saclay, France.

hova
Télécharger la présentation

Challenges in Strongly Correlated Electron Systems: A Dynamical Mean Field Theory Perspective

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Challenges in Strongly Correlated Electron Systems: A Dynamical Mean Field Theory Perspective Gabriel Kotliar and Center for Materials Theory & CPHT Ecole Polytechnique Palaiseau & SPHT CEA Saclay, France EPS 21st General Conference of the Condensed matter Division and DPG Spring Meeting March 26 - 31, 2006 In Dresden, Germany $upport : NSF -DMR DOE-Basic Energy Sciences . Chaire Blaise Pascal Fondation de l’Ecole Normale.

  2. Fermi Liquid Theory(Landau 1957) + [ - ] Density Functional Theory (Kohn Sham 1964) Static Mean Field Theory. Starting point for perturbation theory in the screened interactions (Hedin 1965) Strong Correlation Challenges Approach fails for strongly correlated systems • Fermi Liquid Parameters Non Perturbative. • Regimes where FLT Does NOT Apply. Need new concepts to replace rigid KS bands !

  3. Mott transition: how does the electron go from the localized to itinerant ? Matsuura et. al.(2000) k -(BEDT-TTF)2Cu[N(CN)2]ClLefevre et.al. (2000)Limelette et al.,(2003) Kagawa et al. (2003)

  4. Dynamical Mean Field Theory. Cavity Construction.A. Georges and G. Kotliar PRB 45, 6479 (1992).Inspiration: Weiss (1907), Onsager (1936), DMFT for spin glasses, Fermions in d=∞ Metzner and Vollhardt (1989) Reviews: A. Georges W. Krauth G.Kotliar and M. Rozenberg RMP (1996)G. Kotliar and D. Vollhardt Physics Today (2004).

  5. Mean-Field : Classical vs Quantum IPT: Georges Kotliar (1992). . QMC: M. Jarrell, (1992), NCA T.Pruschke D. Cox and M. Jarrell (1993), ED:Caffarel Krauth and Rozenberg (1994) Projective method: G Moeller (1995). NRG: R. Bulla et. al. PRL 83, 136 (1999) ,……………………………………... • Pruschke et. al Adv. Phys. (1995) • Georges et. al RMP (1996) Classical case Quantum case Hard!!! Easy!!! QMC: J. Hirsch R. Fye (1986) NCA : T. Pruschke and N. Grewe (1989) PT : Yoshida and Yamada (1970) NRG: Wilson (1980) A. Georges, G. Kotliar (1992)

  6. DMFT Qualitative Phase diagram of a frustrated Hubbard model at integer filling T/W Synthesis: Brinkman Rice Hubbard Castellani et.al. Kotliar Ruckenstein Fujimori

  7. Interaction with Experiments. V2O3:Anomalous transfer of spectral weight T=170 T=300 M. Rozenberg G. Kotliar H. Kajueter G Thomas D. Rapkine J Honig and P Metcalf Phys. Rev. Lett. 75, 105 (1995)

  8. Photoemission measurements and Theory V2O3 Mo, Denlinger, Kim, Park, Allen, Sekiyama, Yamasaki, Kadono, Suga, Saitoh, Muro, Metcalf, Keller, Held, Eyert, Anisimov, Vollhardt PRL . (2003) . NiSxSe1-xMatsuura Watanabe Kim Doniach Shen Thio Bennett (1998) Poteryaev et.al. (to be published)

  9. Spinodals and Ising critical endpoint. Theory: Castellani et.al PRL 43, 1957 (1979); Kotliar et.al. PRL84, 5180 (2003)Observation in V2O3 :P. Limelette et.al. Science 302, 89 (2003)

  10. Electronic Structure Meets DMFT LDA+DMFT • Functional formulations, life without U • Further extensions, clusters, GW+DMFT … V. Anisimov, A. Poteryaev, M. Korotin, A. Anokhin and G. Kotliar, J. Phys. Cond. Mat. 35, 7359 (1997). Lichtentsein and Katsnelson. PRB 57,6884 (1998). Almbladh et.al.(1999), Chitra and Kotliar (2000) (2001). Savrasov Kotliar and Abrahams (2001) Large Number of Groups and Many Compounds have been studied.

  11. Localization Delocalization in the Actinides The f electrons in Plutonium are close to a localization-delocalization transition (Johansson, 1974). Mott Transition d a after G. Lander, Science (2003). Modern understanding of this phenomena using functional approach toDMFT. Savrasov et.al. (2001-2005)

  12. DMFT Phonons in fcc d-Pu ( Dai, Savrasov, Kotliar,Ledbetter, Migliori, Abrahams, Science, 9 May 2003) Experiments at the European Synchrotron Radiation Facility, (Wong, Krisch, Farber, Occelli, Schwartz,Chiang,Wall, Boro and Xu et.al, Science, 22 August 2003)

  13. Cluster DMFT: removes limitations of single site DMFT • No k dependence of the self energy. • No d-wave superconductivity. • No Peierls dimerization. • No (R)valence bonds. Reviews: Georges et.al. RMP(1996). Th. Maier, M. Jarrell, Th.Pruschke, M.H. Hettler RMP (2005); Kotliar Savrasov et. .al. RMP in Press.

  14. Two Site Cellular DMFT (G.. Kotliar et.al. PRL (2001))in the 1D Hubbard modelM.Capone M.Civelli V. Kancharla C.Castellani and GK PRB 69,195105 (2004) U/t=4.

  15. Doping Driven Mott transiton at low temperature, in 2d (U=16 t=1, t’=-.3 ) Hubbard model Spectral Function A(k,ω→0)= -1/π G(k, ω→0) vs k K.M. Shen et.al. 2004 Antinodal Region 2X2 CDMFT Nodal Region Civelli et.al. PRL 95 (2005)

  16. Conclusion • Controlled, first principles, many body studies of correlated materials. • Finite T Mott transition in 3d . Single site DMFT worked well! • Lower T, 2d ? Will CDMFT on a plaquette help us generate the right concepts? • New RG methods built around DMFT ?

More Related