Related papers: The McCoy-Wu Model in the Mean-field Approximation
Strange metals defy the quasiparticle description of conventional metals, exhibiting a linear in temperature ($T$-linear) resistivity in a broad temperature range. It has become increasingly clear that, together with $T$-linear resistivity,…
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 report field and temperature dependent measurements of the thermoelectric power (TEP) across the pseudo-metamagnetic transition (MMT) in CeRu$_2$Si$_2$. We applied the thermoelectric gradient parallel and perpendicular to the field along…
We present a theory for disordered interacting electrons that can describe both the Mott and the Anderson transition in the respective limits of zero disorder and zero interaction. We use it to investigate the T=0 Mott-Anderson transition…
We report linear thermal expansion and magnetostriction measurements for CeRu$_2$Si$_2$ in magnetic fields up to 52.6 mT and at temperatures down to 1 mK. At high temperatures, this compound showed Landau-Fermi-liquid behavior: The linear…
We study ferromagnetic transition in three-dimensional double-exchange model containing impurities. The influence of both spin fluctuations and impurity potential on conduction electrons is described in coherent potential approximation. In…
In order to elucidate the nature of the ground state in the heavy-electron system PrInAg_2, we measured its specific heat for temperatures between 60 mK and 2 K in magnetic fields up to 9 T. The peak maximum of the low temperature anomaly…
We investigate the periodic Anderson model with $\bm{k}$-dependent $c$-$f$ mixing reproducing the point nodes of the hybridization gap by using the dynamical mean-field theory combined with the exact diagonalization method. At low…
The low Curie temperature (T_C approx 28K) and small ordered moment (M_0 approx 0.17 mu_B f.u.^-1) of ZrZn2 make it one of the few examples of a weak itinerant ferromagnet. We report results of susceptibility, magnetization, resistivity and…
The distributions $P(X)$ of singular thermodynamic quantities in an ensemble of quenched random samples of linear size $l$ at the critical point $T_c$ are studied by Monte Carlo in two models. Our results confirm predictions of Aharony and…
Prior to the onset of the ferromagnetic transition in semimetallic EuB_6, unusual magnetic and electric behavior have been reported. Using a highly sensitive magneto-optical imaging (MOI) technique, we visualize the behavior of magnetic…
The magnetic properties of Cu97Co3 and Cu90Co10 granular alloys were measured over a wide temperature range (2 to 300K). The measurements show an unusual temperature dependence of the coercive field. A generalized model is proposed and…
We study the microscopic model of electrons in the partially-filled lowest Landau level interacting via the Coulomb potential by the diagrammatic theory within the GW approximation. In a wide range of filling fractions and temperatures, we…
We present a study of the magnetic properties of Zr1-xNbxZn2, using an Arrott plot analysis of the magnetization. The Curie temperature TC is suppressed to zero temperature for Nb concentration xC=0.083+/-0.002, while the spontaneous moment…
We study the random-field Ising model with long-range interactions and show the exactness of the mean-field theory under certain mild conditions. This is a generalization of the result of Mori for the non-random and spin-glass cases. To…
Ferromagnetism in one dimension is a novel observation which has been reported in a recent work (P. Gambardella et.al., Nature {\bf 416}, 301 (2002)), anisotropies are responsibles in that relevant effect. In the present work, another…
The number of monomers, in a monomer-dimer mean-field model with an attractive potential, fluctuates according to the central limit theorem when the parameters are outside the critical curve. At the critical point the model belongs to the…
We provide a new criterion based on graph duality to predict whether the 3-state Potts antiferromagnet on a plane quadrangulation has a zero- or finite-temperature critical point, and its universality class. The former case occurs for…
Specific heat and magnetization results as a function of field on single- and poly-crystalline samples of Ce(1-x)La(x)RhIn(5) show 1.) a specific heat gamma of about 100 mJ/moleK^2 (in agreement with recent dHvA results of Alvers et al.);…
Homogeneous melting of superheated crystals at constant energy is a dynamical process, believed to be triggered by the accumulation of thermal vacancies and their self-diffusion. From microcanonical simulations we know that if an ideal…