Coherence in the Two Kondo Impurity Problem
arXiv:cond-mat/0607426
Abstract
We show through a perturbative and an exact calculation using Wilson's renormalization methods that in the problem of two interacting Kondo impurities, on-site potential scattering generates a quantum-tunneling between the two impurities through a marginally relevant operator. The magnitude of this tunneling depends on the spin-correlation between the two impurities. For exchange interactions between the moments comparable to the Kondo energy , is typically much larger than . This implies that the heavy-fermion mass in this interesting range is determined by rather than . The importance of these results for experiments in coupled Kondo dots is also pointed out.
4 pages, 5 figures. Revised version