Observation of bias-induced resonant tunneling peak splitting in a quantum dot

We have observed that, in zero magnetic field, a dc bias across a lateral confined quantum dot (QD) splits each resonant peak in the differential conductance versus the gate voltage measurement into two. The splitting is nearly linear with the applied bias V_D. Temperature-dependence study indicates that the corresponding energy separation between the two splitting peaks is close to eV_D. A model is proposed that explains this splitting in terms of the bias-induced shifting of energy levels in the QD and the splitting of the Fermi level. Using our model, the bias-induced energy level shift in the QD can be calculated.