Electron transport properties of a parallel-coupled tri-quantum-dot system irradiated by a time-dependent external field

The photon-assisted electron transport properties through a parallel-coupled tri-quantum-dot system are studied using the time-dependent non-equilibrium Green's function theory. When a time-dependent external field irradiates a parallel-coupled three-quantum-dot system, the interaction between photons and electrons provides more novel transport characteristics. The average current can be switched between zero and non-zero by controlling the level of the time-dependent external field, indicating that an optically-controlled quantum switch can be realized. The time-dependent external field makes it more advantageous for the system to be designed as a magnetic-controlled quantum switch. If the magnetic flux and Rashba spin orbit coupling interaction are simultaneously considered, the average current exhibits a spin polarization phenomenon. For the spin down current, the bound states are formed as the magnetic flux takes an appropriate value, which greatly enhances the spin polarization. These research results are expected to contribute to the design of future quantum function devices.