https://doi.org/10.1140/epjb/e2012-30198-7
Regular Article
Effects of non-local spin fluctuations in the orbital-selective Mott transition
1 Max-Planck-Institut für
Mikrostrukturphysik, Weinberg
2, 06120
Halle,
Germany
2 Institut für Physik,
Martin-Luther-Universität Halle-Wittenberg, 06099
Halle,
Germany
a
e-mail: bnapitu@mpi-halle.mpg.de
Received:
5
March
2012
Received in final form:
8
May
2012
Published online:
10
October
2012
Employing the extended dynamical mean field theory (EDMFT) and the quantum Monte Carlo (QMC) method, we investigate the effect of the spatial fluctuations in the two-band Hubbard model with anisotropic bandwidth in the vicinity of the Mott metal-insulator transition. At half filling, we demonstrate that while the inclusion of the non-local spin-spin interaction amounts to enhancing the correlation and suppressing the metallic character, the orbitally selective Mott transition (OSMT) remains stable for various strengths of the non-local correlation. The same is true when the system is doped away from half filling. The OSMT phase is evidenced at low dopant concentration and the simultaneous metallic phase emerges at overdoped regime. From the analysis of the self energy, it follows that the nature of the metallic phase upon doping violates the Fermi liquid character and persists at considerably large doping. Our theory also offers a new perspective for the investigation of the non-local fluctuation in the multi-orbital system within the single-site scheme.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2012