Numerical Renormalization-group Computation of Specific Heats. / Calor específico do modelo de Anderson de uma impureza por grupo de renormalização numérico

AUTOR(ES)

Sandra Cristina Costa

DATA DE PUBLICAÇÃO

1995

RESUMO

The specific heat and the entropy of the one-impurity symmetric Anderson Model are calculated using the Numerical Renormalization Group (NRG). The heart of the method is the logarithmic discretization of the metal conduction band where the impurity is coupled. However, this discretization, inherent in the method, introduces oscillations in the thermodynamical properties. For the susceptibility it is not so critical but for the specific heat the usual calculation is prohibitive. To overcome this difficulty, we use the new procedure called interleaved that was developed to calculate the susceptibility of two-impurity models. In order to reduce the matrices and computation time, use is made of the axial charge operator recently defined in the two-impurity Kondo Model context and that is conserved by the symmetric Anderson Hamiltonian. The curves obtained are compared with exacts results of Bethe ansatz and Resonant Level Model.

ASSUNTO(S)

magnetic alloys kondo efect discretização logarítmica. magnetization ligas magnéticas efeito kondo logarithmic discretization magnetização modelo de anderson modelo de anderson

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