Exact and approximate results for the Anderson impurity model

Jaime Ferrer

G. Shankar Ganesh, Joseph Maciejko

Jay D. Mancini, Charles D. Potter, Samuel P. Bowen

We report preliminary results of convergence properties for nonperturbative resolvent approximations to Anderson-like models of magnetic ions in metals. Our study is initially focused on the spin- 1/2 Anderson model for magnetic impurities, but the methods studied can include multiplet and crystal-field effects which are needed for more accurate descriptions of real systems. We will compare the nonperturbative Lanczos method (tridiagonalization) and similar truncation schemes to exact ground-state energies for the impurity model and assess the efficacy of these nonperturbative approaches to understanding the Anderson lattice, heavy fermions, and other strongly interacting electronic systems.

Shailesh Chandrasekharan A, Jaebeom Yoo, Harold U. Baranger

Jay D. Mancini, William J. Massano, Charles D. Potter +1 more

Using the nonperturbative Lanczos recursion scheme an analytic approximation to the ground-state energy of the single-impurity Anderson model is obtained. Calculations are carried out to a 5\ifmmode\times\else\texttimes\fi{}5 matrix truncation. Comparisons are made with the exact Bethe-ansatz result.

G. Polatsek, K. W. Becker, Vilen Zevin