Magnetic phases near the Van Hove singularity in s- and d-band Hubbard models
(1997) In Physical Review B 56(6). p.3159-3159- Abstract
- We investigate the magnetic instabilities of the nondegenerate (s-band) and a degenerate (d-band) Hubbard model in two dimensions using many-body effects due to particle-particle diagrams and Hund’s rule local correlations. The density of states and the position of the Van Hove singularity change depending on the value of next-nearest-neighbor hopping t′. The Stoner parameter is strongly reduced in the s-band case, and ferromagnetism survives only if the electron density is small and the band has flat regions. Due to next-nearest-neighbor hopping there are flat regions in Γ−X and Γ−Y directions. In contrast, for the d-band case the reduction of the Stoner parameter which follows from particle-particle correlations is much smaller and... (More)
- We investigate the magnetic instabilities of the nondegenerate (s-band) and a degenerate (d-band) Hubbard model in two dimensions using many-body effects due to particle-particle diagrams and Hund’s rule local correlations. The density of states and the position of the Van Hove singularity change depending on the value of next-nearest-neighbor hopping t′. The Stoner parameter is strongly reduced in the s-band case, and ferromagnetism survives only if the electron density is small and the band has flat regions. Due to next-nearest-neighbor hopping there are flat regions in Γ−X and Γ−Y directions. In contrast, for the d-band case the reduction of the Stoner parameter which follows from particle-particle correlations is much smaller and ferromagnetism survives to a large extent. Inclusion of local spin-spin correlations has a limited destabilizing effect on the magnetic states. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/8820562
- author
- Fleck, Marcus ; Oleś, Andrzej M. and Hedin, Lars LU
- organization
- publishing date
- 1997
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review B
- volume
- 56
- issue
- 6
- pages
- 3159 - 3159
- publisher
- American Physical Society
- external identifiers
-
- scopus:0000924433
- ISSN
- 1550-235X
- DOI
- 10.1103/PhysRevB.56.3159
- language
- English
- LU publication?
- yes
- additional info
- DOI:http://dx.doi.org.ludwig.lub.lu.se/10.1103/PhysRevB.56.3159
- id
- f7beac45-b240-4a58-b68e-adfff4cf37a8 (old id 8820562)
- date added to LUP
- 2016-04-04 14:22:35
- date last changed
- 2022-04-24 05:52:34
@article{f7beac45-b240-4a58-b68e-adfff4cf37a8, abstract = {{We investigate the magnetic instabilities of the nondegenerate (s-band) and a degenerate (d-band) Hubbard model in two dimensions using many-body effects due to particle-particle diagrams and Hund’s rule local correlations. The density of states and the position of the Van Hove singularity change depending on the value of next-nearest-neighbor hopping t′. The Stoner parameter is strongly reduced in the s-band case, and ferromagnetism survives only if the electron density is small and the band has flat regions. Due to next-nearest-neighbor hopping there are flat regions in Γ−X and Γ−Y directions. In contrast, for the d-band case the reduction of the Stoner parameter which follows from particle-particle correlations is much smaller and ferromagnetism survives to a large extent. Inclusion of local spin-spin correlations has a limited destabilizing effect on the magnetic states.}}, author = {{Fleck, Marcus and Oleś, Andrzej M. and Hedin, Lars}}, issn = {{1550-235X}}, language = {{eng}}, number = {{6}}, pages = {{3159--3159}}, publisher = {{American Physical Society}}, series = {{Physical Review B}}, title = {{Magnetic phases near the Van Hove singularity in s- and d-band Hubbard models}}, url = {{http://dx.doi.org/10.1103/PhysRevB.56.3159}}, doi = {{10.1103/PhysRevB.56.3159}}, volume = {{56}}, year = {{1997}}, }