(color online) (a) Magnetoconductance (MC) traces measured at a temperature of 10 mK from V_g = −1.2 V to V_g = −0.3 V, corresponding to the same region denoted by the orange square in Fig. 2(a). The step of V_g between adjacent traces is 0.06 V. (b) ∆G as a function of B and V_g obtained by subtracting the conductance at zero magnetic field G(0) from the MC traces. It can be clearly seen that ∆G exhibits a periodic-like behaviour as B and V_g is varied.