Figure 4: (a) Structure of single electron transistor, (b) equivalent schematic diagram of SET. The quantum dot is connected to the source and drain electrodes through small tunnel barriers. The potential in the quantum dot can be modified by the gate electrode which is capacitively coupled to the quantum dot, 𝑉 𝐺 = ( 2 𝑛 + 1 ) 𝑒 / 2 𝐶 𝐺 . The DC bias ( 𝑉 𝐷 ) is applied and the current is measured as a function of 𝑉 𝐷 and 𝑉 𝐺 . The SET’s parameters are 𝐶 𝑆 , 𝐶 𝐷 , 𝐶 𝐺 , Γ 𝑆 , and Γ 𝐷 .