arXiv:cond-mat/0507682 · physica status solidi (b)

Orbital‐selective Mott transitions in the 2‐band Jz‐model: a high‐precision quantum Monte Carlo study

P. G. J. van Dongen, C. Knecht, N. Blümer

Published Nov 24, 2005• 12 citations

Abstract

Abstract Using high‐precision quantum Monte Carlo (QMC) simulations within the framework of dynamical mean field theory (DMFT), we show that the anisotropic degenerate two‐orbital Hubbard model contains two consecutive orbital‐selective Mott transitions (OSMTs) even in the absence of spin‐flip terms and pair‐hopping processes. In order to reveal the second transition we carefully analyze the low‐frequency part of the self‐energy and the local spectral functions. This paper extends our previous work to lower temperatures. We discuss the nature – in particular the order – of both Mott transitions and list various possible extensions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

DOI: 10.1002/pssb.200562449

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Reply to "Comment on `Orbital-selective Mott transitions in the anisotropic two-band Hubbard model at finite temperatures'"

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In a Comment [cond-mat/0506138] on our recent e-print [cond-mat/0505106] Liebsch claimed "excellent correspondence" between our high-precision quantum Monte-Carlo (QMC) data for the anisotropic two-band Hubbard model with Ising type exchange couplings and his earlier QMC results. Liebsch also claimed that the sequence of two orbital-selective Mott transitions, identified by us in this model, had already been reported in his earlier work. Here we demonstrate that both claims are incorrect. We establish that Liebsch's previous QMC estimates for the quasiparticle weight Z have relative errors exceeding 100% near transitions and cannot be used to infer the existence of a second Mott transition (for U_{c2}~2.5). We further show that Liebsch's attribution of our findings to his own earlier work is disproved by the published record. Consequently, the Comment is unwarranted; all results and formulations of our e-print remain valid.

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