Related papers: Gr\"uneisen parameter studies on heavy fermion qua…
The Hubbard model on fcc-type lattices is studied in the dynamical mean-field theory of infinite spatial dimensions. At intermediate interaction strength finite temperature Quantum Monte Carlo calculations yield a second order phase…
A growing body of evidence suggests that the quantum critical behavior at the onset of magnetism in heavy fermion systems can not be understood in terms of a simple quantum spin density wave. This talk will discuss the consequences of this…
Magnetic properties of quark matter at finite temperature are discussed by evaluating the magnetic susceptibility. Combining the microscopic calculation of the self-energy for quarks as well as the screening effects for gluons with…
We present a theory of the scaling behavior of the thermodynamic, transport and dynamical properties of a three-dimensional metal governed by $d$-dimensional fluctuations at a quantum critical point, where the electron quasiparticle…
To understand the halfmetallic ferromagnet EuB6 we use the Kondo lattice model for valence and conduction band. By means of a recently developed many-body theory we calculate the electronic properties in the ferromagnetic regime up to the…
We study the thermal and electric transport of a fluid of interacting Dirac fermions using a Boltzmann approach. We include Coulomb interactions, a dilute density of charged impurities and the presence of a magnetic field to describe both…
The thermal expansion coefficient $\alpha$ of MgB$_2$ is revealed to change from positive to negative on cooling through the superconducting transition temperature $T_c$. The Gr\"uneisen function also becomes negative at $T_c$ followed by a…
Results of combined thermal and electrical transport measurements through the magnetic field-induced quantum critical point in the heavy-fermion compound YbRh2Si2 are revisited to explore the relationship between the strange-metal behavior,…
The competition between magnetism and Kondo effect is the main effect determining the phase diagram of heavy fermion systems. It gives rise to a quantum critical point which governs the low temperature properties of these materials.…
We introduce a Heisenberg Hamiltonian for describing the magnetic properties of GaMnAs. Electronic degrees of freedom are integrated out leading to a pairwise interaction between Mn spins. Monte Carlo simulations in large systems are then…
We study strongly correlated electrons on a kagome lattice at 1/6 and 1/3 filling. They are described by an extended Hubbard Hamiltonian. We are concerned with the limit |t|<<V<<U with hopping amplitude t, nearest-neighbor repulsion V and…
Ultracold fermionic alkaline earth atoms confined in optical lattices realize Hubbard models with internal SU(N) symmetries, where N can be as large as ten. Such systems are expected to harbor exotic magnetic physics at temperatures below…
We study uniaxially strained graphene under the influence of non-uniform magnetic fields perpendicular to the material sample with a coordinate independent strain tensor. For that purpose, we solve the Dirac equation with anisotropic Fermi…
Motivated by the physics of graphene, we consider a model of N species of 2+1 dimensional four-component massless Dirac fermions interacting through a 3D instantaneous Coulomb interaction. We show that in the limit of infinitely strong…
We exploit the grassmannian nature of the variables involved in the path integral expression of the grand canonical partition function for self--interacting fermionic models to show, in one-space dimension, a general relation among the…
With the aim of improving the performance of classical paramagnetic salts for adiabatic refrigeration processes at the sub-Kelvin range, relevant thermodynamic parameters of some new Yb-based intermetallic compounds are analyzed and…
Magnetic materials are typically described in terms of the Heisenberg model, which provides an accurate account of thermodynamic properties when combined with first principles calculations. This approach is usually based on an energy…
The Gr\"uneisen ratio (GR) has emerged as a superb tool for the diagnosis of quantum phase transitions, which diverges algebraically upon approaching critical points of continuous phase transitions. However, this paradigm has been…
The Kondo and Periodic Anderson Model (PAM) are known to provide a microscopic picture of many of the fundamental properties of heavy fermion materials and, more generally, a variety of strong correlation phenomena in $4f$ and $5f$ systems.…
We analyze quantal Brownian motion in $d$ dimensions using the unified model for diffusion localization and dissipation, and Feynman-Vernon formalism. At high temperatures the propagator possess a Markovian property and we can write down an…