Related papers: Thermal and field-induced transitions in ferroquad…
Here we present a new perspective to the breakdown of ferromagnetic order in two-dimensional spin-lattice models employing the rotation of the underlying lattice. Using an Ising spin system on a square lattice as a prototype, we demonstrate…
A symmetric spin-1/2 Ising-Heisenberg diamond chain with the Ising four-spin interaction is exactly solved by means of the generalized decoration-iteration mapping transformation. The ground state, the magnetization process and…
We present a high-field study of the strongly anisotropic easy-plane square lattice $S$ = 2 quantum magnet Ba$_{2}$FeSi$_{2}$O$_{7}$. This compound is a rare high-spin antiferromagnetic system with very strong easy-plane anisotropy, such…
Using the Kondo lattice model with classical spins in infinite dimension, magnetic phase transition in the perovskite-type $3d$ transition-metal oxide (La,Sr)MnO$_3$ is theoretically studied. On the Bethe lattice, the self-consistency…
We use the dynamical cluster approximation, with a quantum Monte Carlo cluster solver on clusters of up to 16 orbitals, to investigate the evolution of the Fermi surface across the magnetic order-disorder transition in the two-dimensional…
Using a non-Abelian density matrix renormalization group method we determine the phase diagram of the Kondo lattice model in one dimension, by directly measuring the magnetization of the ground-state. This allowed us to discover a second…
The magnetic field dependent phase diagram of the ferroelectric material ${\rm Ho}_{1-x}Y_{x}MnO_{3}$ has been investigated for x = 0, 0.6, and 0.8 for fields directed along both the ab in-plane and c-axis basal plane directions. Dielectric…
We use dynamical mean-field theory to study how electronic transport in multi-orbital metals is influenced by correlated (nominally) empty orbitals that are in proximity to the Fermi level. Specifically, we study 2 + 1 orbital and 3 + 2…
We use a novel Monte Carlo method to study the Mott transition in an anisotropic triangular lattice. The real space approach, retaining extended spatial correlations, allows an accurate treatment of non trivial magnetic fluctuations in this…
We show by extensive Monte Carlo simulations that we need a multi-spin interaction in addition to pairwise interactions in order to reproduce the temperature dependence of the experimental magnetization observed in the perovskite compound…
Spatially extended localized spins can interact via indirect exchange interaction through Friedel oscillations in the Fermi sea. In arrays of localized spins such interaction can lead to a magnetically ordered phase. Without external…
There is a new class of two-dimensional magnetic materials polymeric iron (III) acetate fabricated recently in which Fe ions form a star lattice. We study the thermodynamics of Ising spins on the star lattice with exact analytic method and…
We study the S=1/2 quantum antiferromagnetic XY model on finite triangular lattices with N sites in both longitudinal and transverse magnetic fields. We calculate physical quantities in the ground state using a diagonalization for spins $N…
The magnetic phase diagram and the thermodynamic properties of a square lattice containing antiferromagnetically coupled spin-1/2 triangles are studied. A Heisenberg Hamiltonian with three strong intra-triangle exchange coupling constants…
The breakdown of the lattice Kondo effect in local-moment metals can lead to non-trivial forms of quantum criticality and a variety of non-Fermi-liquid phases. Given indications that Kondo-breakdown transitions involve criticality not only…
We study the quantum phase transition from an antiferromagnetic metal to a heavy fermion metal in the Kondo lattice model. Based on the strong coupling approach we {\it first} diagonalize the Kondo coupling term. Since this strong coupling…
We introduce a two-band Kondo-lattice model to describe ferromagnetic half-metals with local magnetic moments. In a model study, the electronic and magnetic properties are presented by temperature dependent magnetization curves,…
We study a nonequilibrium Ising model that stochastically evolves under the simultaneous operation of several spin-flip mechanisms. In other words, the local magnetic fields change sign randomly with time due to competing kinetics. This…
In a recent paper of Nandkishore and Senthil [arxiv:1201.5998 (2012)], a concept of orthogonal metal has been introduced to reinterpret the disordered state of slave-spin representation in the Hubbard model as an exotic gapped metallic…
We consider orbital magnetic field effects in a spin liquid phase of a half-filled triangular lattice Hubbard system close to the Mott transition, continuing an earlier exploration of a state with spinon Fermi surface. Starting from the…