Autor(es): De Souza Melo, Bruno Max ; Da Silva, Luis G. G. V. Dias ; Rocha, Alexandre Reily [UNESP] ; Lewenkopf, Caio
Data: 2020
Identificador Persistente: http://hdl.handle.net/11449/199884
Origem: Oasisbr
Assunto(s): electronic transport; impurity solvers; molecular electronics; quantum dots; electronic transport; electronic transport; impurity solvers; impurity solvers; molecular electronics; molecular electronics; quantum dots; quantum dots
Made available in DSpace on 2020-12-12T01:51:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01
We study the single impurity Anderson model (SIAM) using the equations of motion method (EOM), the non-crossing approximation (NCA), the one-crossing approximation (OCA), and Wilson's numerical renormalization group (NRG). We calculate the density of states and the linear conductance focusing on their dependence on the chemical potential and on the temperature paying special attention to the Kondo and Coulomb blockade regimes for a large range of model parameters. We report that some standard approximations based on the EOM technique display a rather unexpected poor behavior in the Coulomb blockade regime even at high temperatures. Our study offers a critical comparison between the different methods as well as a detailed compilation of the shortcomings and limitations due the approximations involved in each technique, thus allowing for a cost-benefit analysis of the different solvers that considers both numerical precision and computational performance.
Instituto de Física Universidade Federal Fluminense
Universidade de Sao Paulo Instituto de Fisica, Rua do Matao 1371
Instituto de Física Teórica Sao Paulo State University (UNESP)
Instituto de Física Teórica Sao Paulo State University (UNESP)
