Dc. Ralph et Ra. Buhrman, KONDO-ASSISTED AND RESONANT-TUNNELING VIA A SINGLE CHARGE TRAP - A REALIZATION OF THE ANDERSON MODEL OUT OF EQUILIBRIUM, Physical review letters, 72(21), 1994, pp. 3401-3404
We have observed both Kondo-assisted tunneling and simple resonant tun
neling via a single charge trap state in the voltage-dependent differe
ntial conductance of a point-contact tunnel barrier. From the resonant
tunneling signal, we determine parameters of the Anderson model gover
ning the state. This allows comparison of the measured Kondo-assisted
signal to results of the Anderson model. The Kondo signal is not adequ
ately described by perturbation theory, but is in qualitative agreemen
t with nonperturbative calculations.