Navegação Ciências Exatas e da Terra por Assunto "Efeito kondo"
Resultados 1-14 de 14
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Application of the underscreened Kondo lattice model to neptunium compounds
(2012) [Artigo de periódico]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 ... -
Band-filling effects on Kondo-lattice properties
(2003) [Artigo de periódico]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) [Artigo de periódico]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 ... -
Cumulant expansion of the periodic Anderson model : general derivation
(1994) [Artigo de periódico]We extend to the periodic Anderson model (PAM) the diagrammatic expansion in cumulants that was employed by Hubbard to study his model of a narrow band of strongly correlated electrons. The PAM is a lattice of localized ... -
Effect of band filling in the Kondo lattice : a mean-field approach
(1999) [Artigo de periódico]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 ... -
Hall effect in Ce 1-x Y x/Pd 3 mixed-valence alloys
(1985) [Artigo de periódico]Mixed-valence and Kondo lattice systems exhibit large anomalous Hall coefficients with a striking change of sign at low temperature in severa! systems (CePd3, CeCu6, ... , etc.). We have studied the Hall effect of Ce1-x ... -
Kondo-like behavior and GMR effect in granular Cu90Co10 microwires
(2017) [Artigo de periódico]We observed a significant increase of the giant magnetoresistance (GMR) effect (up to 32% after the adequate annealing) and Kondo-like behavior in Cu90Co10 glass-coated microwires. Observed enhancement of the GMR effect ... -
Magnetic susceptibility and specific heat of the anderson lattice : perturbative expansion around the atomic limit
(1992) [Artigo de periódico]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 ... -
Phase diagram for the Anderson lattice model
(2000) [Artigo de periódico]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 ... -
Quantum critical point in the spin glass-Kondo transition in heavy-fermion systems
(2004) [Artigo de periódico]The Kondo–spin glass competition is studied in a theoretical model of a Kondo lattice with an intrasite Kondo-type exchange interaction treated within the mean-field approximation, an intersite quantum Ising exchange ... -
Revisited doniach diagram : influence of short-range antiferromagnetic correlations in the Kondo lattice
(1997) [Artigo de periódico]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 ... -
Spin-glass freezing in Kondo-lattice compounds
(2001) [Artigo de periódico]A theory is presented that describes a spin-glass phase at finite temperatures in Kondo-lattice systems with an additional Ruderman–Kittel–Kasuya–Yosida interaction represented by long range, random couplings among localized ... -
The S=1 underscreened anderson lattice model for uranium compounds
(2011) [Artigo de periódico]Magnetic properties of uranium and neptunium compounds showing coexistence of the Kondo e®ect and ferromagnetic order are investigated within the degenerate Anderson Lattice Hamiltonian, describing a 5f2 electronic ... -
Underscreened Kondo lattice model applied to heavy fermion uranium compounds
(2007) [Artigo de periódico]We present theoretical results for the underscreened Kondo lattice model with localized S=1 spins coupled to a conduction band through a Kondo coupling, JK, and interacting among them ferromagnetically. We use a fermionic ...
