2008年8月
A finite-frequency functional renormalization group approach to the single impurity Anderson model
JOURNAL OF PHYSICS-CONDENSED MATTER
- ,
- ,
- ,
- ,
- ,
- 巻
- 20
- 号
- 34
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1088/0953-8984/20/34/345205
- 出版者・発行元
- IOP PUBLISHING LTD
We use the Matsubara functional renormalization group (FRG) to describe electronic correlations within the single impurity Anderson model. In contrast to standard FRG calculations, we account for the frequency dependence of the two-particle vertex in order to address finite-energy properties (e. g, spectral functions). By comparing with data obtained from the numerical renormalization group (NRG) framework, the FRG approximation is shown to work well for arbitrary parameters (particularly finite temperatures) provided that the electron-electron interaction U is not too large. We demonstrate that aspects of (large U) Kondo physics which are described well by a simpler frequency-independent truncation scheme are no longer captured by the 'higher-order' frequency-dependent approximation. In contrast, at small to intermediate U the results obtained by the more elaborate scheme agree better with NRG data. We suggest to parametrize the two-particle vertex not by three independent energy variables but by introducing three functions each of a single frequency. This considerably reduces the numerical effort to integrate the FRG flow equations.
- リンク情報
- ID情報
-
- DOI : 10.1088/0953-8984/20/34/345205
- ISSN : 0953-8984
- Web of Science ID : WOS:000258317600008