Field dependent dynamics in the metallic regime of the half-filled Hubbard model

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.

8 pages, 10 figures

References in corpus (5)

• Field dependent quasiparticles in the infinite dimensional Hubbard model
• Quasiparticle properties of strongly correlated electron systems with itinerant metamagnetic behavior
• Dynamical Mean-Field Theory - from Quantum Impurity Physics to Lattice Problems
• Interplay between strong correlations and magnetic field in the symmetric periodic Anderson model
• Magnetoresistance in paramagnetic heavy fermion metals

Cited by in corpus (4)

• Properties of an almost localized Fermi liquid in applied magnetic field revisited: Statistically consistent Gutzwiller approach
• Magnetic field-dependent dynamics and field-driven metal-to-insulator transition of the half-filled Hubbard model: A DMFT+DMRG study
• Spin-selective localization of correlated lattice fermions
• Feasibility of a metamagnetic transition in correlated systems