title: Feasibility of a metamagnetic transition in correlated systems.
abstract: The long-standing issue of the competition between the magnetic field and the Kondo effect, favoring, respectively, triplet and singlet ground states, is addressed using a cluster slave-rotor mean-field theory for the Hubbard model and its spin-correlated, spin-frustrated extensions in two dimensions. The metamagnetic jump is established and compared with earlier results of dynamical mean-field theory. This approach also reproduces the emergent super-exchange energy scale in the insulating side. A scaling is found for the critical Zeeman field in terms of the intrinsic coherence scale just below the metal-insulator transition, where the critical spin fluctuations are soft. The conditions required for metamagnetism to appear at a reasonable field are also underlined. Gutzwiller analysis on the two-dimensional Hubbard model and a quantum Monte Carlo calculation on the Heisenberg spin system are performed to check the limiting cases of the cluster slave-rotor results for the Hubbard model. Low-field scaling features for magnetization are discussed.
authors.affiliation: Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
authors.forename: Swagata
authors.initials: S
authors.lastname: Acharya
authors.forename: Amal
authors.initials: A
authors.lastname: Medhi
authors.forename: N S
authors.initials: NS
authors.lastname: Vidhyadhiraja
authors.forename: A
authors.initials: A
authors.lastname: Taraphder