Tunable zero-field Kondo splitting in a quantum dot
We present detailed low-temperature transport measurements of a single quantum dot formed in an InGaAs/InP heterostructure with a strong tunnel coupling to the source and drain leads. The conventional spin-1/2 Kondo effect is observed for the quantum dot in the N = 9 charge state. By changing the voltages applied to the quantum dot barrier gates, we find a zero-field splitting of the Kondo resonan