Validity of equation-of-motion approach to kondo problem in the large N limit

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Physical Review Letters

OSTI ID:960947

Zhu, Jian-xin ^[1]; Ting, C S ^[2]; Qi, Yunong ^[2]

---

1. Los Alamos National Laboratory
2. UNIV OF HOUSTON

The Anderson impurity model for Kondo problem is investigated for arbitrary orbit-spin degeneracy N of the magnetic impurity by the equation of motion method (EOM). By employing a new decoupling scheme, a self-consistent equation for the one-particle Green function is derived and numerically solved in the large-N approximation. For the particle-hole symmetric Anderson model with finite Coulomb interaction U, we show that the Kondo resonance at the impurity site exists for all N {>=} 2. The approach removes the pathology in the standard EOM for N = 2, and has the same level of applicability as non-crossing approximation. For N = 2, an exchange field splits the Kondo resonance into only two peaks, consist with the result from more rigorous numerical renormalization group (NRG) method. The temperature dependence of the Kondo resonance peak is also discussed.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 960947
• Report Number(s): LA-UR-08-06707; LA-UR-08-6707
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DECOUPLING
EQUATIONS OF MOTION
GREEN FUNCTION
IMPURITIES
INTERACTIONS
KONDO EFFECT
RENORMALIZATION
RESONANCE
SPIN
TEMPERATURE DEPENDENCE