Ferromagnetism in the two-dimensional periodic Anderson model - art. no. 184428

Citation
Cd. Batista et al., Ferromagnetism in the two-dimensional periodic Anderson model - art. no. 184428, PHYS REV B, 6318(18), 2001, pp. 4428
Citations number
40
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICAL REVIEW B
ISSN journal
01631829 → ACNP
Volume
6318
Issue
18
Year of publication
2001
Database
ISI
SICI code
0163-1829(20010501)6318:18<4428:FITTPA>2.0.ZU;2-2
Abstract
Using the constrained-path Monte Carlo method, we studied the magnetic prop erties of the two-dimensional periodic Anderson model for electron fillings between 1/4 and 1/2. We also derived two effective low-energy theories to assist in interpreting the numerical results. For 1/4 filling, we found tha t the system can be a Mott or a charge-transfer insulator, depending on the relative values of the Coulomb interaction and the charge-transfer gap bet ween the two noninteracting bands. The insulator may be a paramagnet or ant iferromagnet. We concentrated on the effect of electron doping on these ins ulating phases. Upon doping we obtained a partially saturated ferromagnetic phase for low concentrations of conduction electrons, if the system were a charge-transfer insulator, we would find that the ferromagnetism is induce d by the well-known Ruderman-Kittel-Kasuya-Yosida interaction. However, we found a novel correlated hopping mechanism inducing the ferromagnetism in t he region where the nondoped system is a Mott insulator. Our regions of fer romagnetism spanned a much smaller doping range than suggested by recent sl ave boson and dynamical mean-field theory calculations, but they were consi stent with that obtained by density-matrix renormalization group calculatio ns of the one-dimensional periodic Anderson model.