Controllability of single electron tunneling and change in Coulomb diamond caused by environmental impedance modulation

Single-electron-tunneling device with variable environmental impedance (Z-SET) is considered. It is numerically shown that resistive environmental impedance can control the Coulomb gap and capacitive environmental impedance degrade the controllability of Z-SET. It is experimentally observed that the Coulomb gap becomes large as the negative gate voltages to control the environmental resistance becomes large. In order to consider the origin of the observed enlargement of the Coulomb gap. The effect of environmental impedance on the shape of the Coulomb diamond is also discussed.