QUENCHING OF OVERCOMPENSATED KONDO IMPURITIES VIA CHANNEL ASYMMETRY

We consider a spin-1/2 impurity interacting with conduction electrons in two different orbital channels via an isotropic spin exchange. The exchange is the same for both channels, but a crystalline field breaks the symmetry between the orbital channels. This corresponds to a spli tting of the conduction electron Gamma(8) into two doublets in the qua drupolar Kondo effect and to the application of an external magnetic f ield in the electron assisted tunneling of an atom in a double-well po tential. We study the ground-state properties of the impurity as a fun ction of the magnetic and crystalline fields. The crystalline field qu enches the critical behavior of the overcompensated fixed point: The i mpurity ground state is a singlet.