MPI für Festkörperforschung / FKF Publikationen 2006 |
|Quantum Monte Carlo study for multiorbital systems with preserved spin and orbital rotational symmetries|
|Authors:||Sakai, S.; Arita, R.; Held, K.; Aoki, H.|
|Date of Publication (YYYY-MM-DD):||2006|
|Title of Journal:||Physical Review B|
|Issue / Number:||15|
|Sequence Number of Article:||155102|
|Abstract / Description:||We propose to combine the Trotter decomposition and a series expansion
of the partition function for Hund's exchange coupling in a quantum
Monte Carlo (QMC) algorithm for multiorbital systems that preserves
spin and orbital rotational symmetries. This enables us to treat the
Hund's (spin-flip and pair-hopping) terms, which is difficult in the
conventional QMC method. To demonstrate this, we first apply the
algorithm to study ferromagnetism in the two-orbital Hubbard model
within the dynamical mean-field theory (DMFT). The result reveals that
the preservation of the SU(2) symmetry in Hund's exchange is important,
where the Curie temperature is grossly overestimated when the symmetry
is degraded, as is often done, to Ising (Z(2)). We then calculate the
t(2g) spectral functions of Sr2RuO4 by a three-band DMFT calculation
with tight-binding parameters taken from the local density
approximation with proper rotational symmetry.
|External Publication Status:||published|
|Communicated by:||N. N.|
|Affiliations:||MPI für Festkörperforschung|
|External Affiliations:||Univ Tokyo, Dept Phys, Tokyo 1130033, Japan.
; Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany.
|Identifiers:||ISI:000241723600042 [ID No:1] |
ISSN:1098-0121 [ID No:2]
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