Comment on "Zero-field Kondo Splitting and Quantum-Critical Transition in Double Quantum Dots"

L. VAUGIER, A. A. ALIGIA, AND A. M. LOBOS

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Año: 2007 vol. 99 p. 209 - 701

0031-9007

In a recent Letter, a system containing a noninteracting and a Kondo quantum dot (QD) has been studied. Interesting effects are observed in the spectral density of the Kondo QD due to the nonconstant density of states to which the Kondo QD interacts. For a sidedot configuration, if the width of the spectral desnsity is sufficiently smaller than the Kondo temperature TK, the Kondo peak is split in two. The splitting is interpreted as due to a decrease in the spectral density at the Fermi energy, to satisfy the Friedel sum rule. An alternative interpretation, based on interference between noninteracting resonances is in principle unjustified for a highly correlated system. Here we show that the first interpretation is not correct and provide a justification for the second.TK, the Kondo peak is split in two. The splitting is interpreted as due to a decrease in the spectral density at the Fermi energy, to satisfy the Friedel sum rule. An alternative interpretation, based on interference between noninteracting resonances is in principle unjustified for a highly correlated system. Here we show that the first interpretation is not correct and provide a justification for the second.