Browsing Exact and Earth Sciences by Author "Iglesias, Jose Roberto"
Now showing items 1-20 of 23
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Application of the underscreened Kondo lattice model to neptunium compounds
(2012) [Journal article]The coexistence of Kondo e®ect and ferromagnetic order has been observed in many uranium and neptunium compounds such as UTe or Np2PdGa3. This coexistence can be described within the underscreened Anderson lattice model ... -
Approximate Treatment of a Two-Dimensional Anisotropic Peierls-Hubbard Model
(1993) [Journal article]A Green-function formalism is presented to study a Peierls-Hubbard Hamiltonian in two dimensions. The 1attice consists of parallel dimerized chains with alternating nearest-neighbor hoppings t and t 11 and another hopping ... -
Band-filling effects on Kondo-lattice properties
(2003) [Journal article]We present theoretical results for a Kondo-lattice model with spin-1/2 localized moments, including both the intrasite Kondo coupling and an intersite antiferromagnetic exchange interaction, treated within an extended ... -
Bohm-Aharonov and Kondo effects on tunneling currents in a mesoscopic ring
(1997) [Journal article]We present an analysis of the Kondo effect on the Bohm-Aharonov oscillations of the tunneling currents in a mesoscopic ring with a quantum dot inserted in one of its arms. The system is described by an Andersonimpurity ... -
Doping dependence of the electronic structure and magnetic order in high-tc superconductors
(1994) [Journal article]The local densities of states of an extended Hubbard model describing the Cu02 planes of superconducting cuprates are calculated by means of an approximate treatment that divides the lattice into Cu02 clusters. The exact ... -
Dynamic modular networks model mediated by confinement
(2019) [Journal article]We present a model for network transformation mediated by confinement, as a demonstration of a simple network dynamics that has a direct connection with real world quantities. The model has the capacity of generating complex ... -
Effect of band filling in the Kondo lattice : a mean-field approach
(1999) [Journal article]The usual Kondo lattice, including an antiferromagnetic exchange interaction between nearest-neighboring localized spins, is treated here in a mean-field scheme that introduces two mean-field parameters: one associated ... -
Eletronic and phonomic states of the Holstein-Hubbard dimer of variable length
(1998) [Journal article]We consider a model Hamiltonian for a dimer of length a including all the electronic one- and two-body terms consistent with a single orbital per site, a free Einstein phonon term for a frequency V, and an electronphonon ... -
Green-Function Method for a Mixed-Valence Hamiltonian
(1984) [Journal article]A Green-function diagrammatic method is utilized to calculate the occupation number of a narrow (j) band in a mixed-valence system. The method is a generalization of the Hubbard-1 approximation for a two-band Hamiltonian. ... -
Growth and form of two-dimensional rotating aggregates
(1993) [Journal article]We propose a two-dimensional particle-cluster aggregation model which considers explicitly linear and angular momentum conservation. Each aggregate is grown from a seed of given mass and given initial angular velocity, to ... -
Macroscopic and microscopic perspectives for adoption of technologies in the USA
(2020) [Journal article]Adoption of a new technology depends on many factors. Marketing, advertising, social interactions, and personal convictions are relevant features when deciding to adopt, or not, a new technology. Thus, it is very important ... -
Magnetic susceptibility and specific heat of the anderson lattice : perturbative expansion around the atomic limit
(1992) [Journal article]The Green's functions relevant to the periodic Anderson Hamiltonian are calculated via perturbation theory around the atomic limit. The approximation reproduces exact results in three different limits: zero bandwidth, zero ... -
Mesoscopic magnetic states in metallic alloys with strong electronic correlations : a percolative scenario for CeNi/sub 1-x/Cu/sub x/
(2007) [Journal article]We present evidence for the existence of magnetic clusters of approximately 20 Å in the strongly correlated alloy system CeNi1-xCux (0.7 ≤ x ≤ 0.2) based on small angle neutron scattering experiments as well as the occurrence ... -
Mitosis and growth in biological tissues
(1993) [Journal article]We present a simulation of the growth of a two-dimensional biological cellular system in which the cells experience mitosis whenever the (area)/(perimeter) ratio reaches a critical value. The model also includes the effect ... -
Modeling two-dimensional magnetic domain patterns
(2002) [Journal article]Two-dimensional magnetic garnets exhibit complex and fascinating magnetic domain structures, like stripes, labyrinths, cells, and mixed states of stripes and cells. These patterns do change in a reversible way when the ... -
Phase diagram for the Anderson lattice model
(2000) [Journal article]We study the competition between the Kondo effect and the Ruderman-Kittel-Kasuya-Yosida interaction in the framework of the Anderson lattice model with an extra intersite exchange term. By using an approximation based on ... -
Revisited doniach diagram : influence of short-range antiferromagnetic correlations in the Kondo lattice
(1997) [Journal article]The Kondo lattice model including nearest-neighbor magnetic exchange interactions is studied here in a mean-field approximation describing both the Kondo state and the intersite magnetic correlations. In the case of ... -
Statistical thermodinamics of a two-dimensional cellular system
(1991) [Journal article]The principies of statistical physics are applied to the study of cellular systems. Cells that fill a flat surface are characterized by area, perimeter, and number of sides. A set of constraints is established, taking into ... -
Taxes, inequality, and equal opportunities
(2023) [Journal article]Extreme inequality represents a grave challenge for impoverished individuals and poses a threat to economic growth and stability. Despite the fulfillment of affirmative action measures aimed at promoting equal opportunities, ... -
Temperature dependence of the electric field gradient generated by nearest-neighbor impurity atoms in cubic Ag metal
(1978) [Journal article]The electric quadrupole interactions produced by near-neighbor (nn) and distant-neighbor impurity atoms of Cu, Au, Zn, In, Ga, Al, Sn, and Sb in a cubic Ag lattice are measured as a function of the temperature by the time ...
