Back to Search
Start Over
Field dependent dynamics in the metallic regime of the half-filled Hubbard model
Field dependent dynamics in the metallic regime of the half-filled Hubbard model
- Publication Year :
- 2010
- Publisher :
- arXiv, 2010.
-
Abstract
- A systematic study of the effect of magnetic field (h) on Hubbard model has been carried out at half filling within dynamical mean field theory. In agreement with previous studies, we find a zero temperature itinerant metamagnetic transition, reflected in the discontinuous changes in magnetization as well as in the hysteresis, from a paramagnetic (PM) metallic state to a polarized quasi-ferromagnetic (QFM) state, at intermediate and large interaction strength ($U$). The jump in magnetization vanishes smoothly with decreasing interaction strength, and at a critical $U$, the transition becomes continuous. The region of `coexistence' of the PM and QFM solutions in the field-$U$ plane obtained in this study agrees quantitatively with recent numerical renormalization group calculations, thus providing an important benchmark. We highlight the changes in dynamics and quasiparticle weight across this transition. The effective mass increases sharply as the transition is approached, exhibiting a cusp-like singularity at the critical field,and decreases with field monotonically beyond the transition. We conjecture that the first order metamagnetic transition is a result of the competition between Kondo screening, that tries to quench the local moments, and Zeeman coupling, which induces polarization and hence promotes local moment formation. A comparison of our theoretical results with experiments on $^{3}He$ indicate that, a theory of $^{3}He$ based on the half-filled Hubbard model places it in a regime of intermediate interaction strength.<br />Comment: 8 pages, 10 figures
- Subjects :
- Physics
Zeeman effect
Condensed matter physics
Hubbard model
Strongly Correlated Electrons (cond-mat.str-el)
FOS: Physical sciences
Condensed Matter Physics
Magnetic field
Magnetization
Paramagnetism
symbols.namesake
Condensed Matter - Strongly Correlated Electrons
Effective mass (solid-state physics)
Quasiparticle
symbols
General Materials Science
Condensed Matter::Strongly Correlated Electrons
Critical field
Subjects
Details
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....a4ced0ea579a2b375910c73a92bbee5c
- Full Text :
- https://doi.org/10.48550/arxiv.1006.1457