Electrically tunable electron g factors in coupled InAs/GaAs pyramid quantum dots

The electron g factors of coupled InAs/GaAs quantum dots under external magnetic and electric fields are investigated by using the eight-band kp model. The resonant coupling between the two dots remains under electric fields below 8.2 mV/nm, and is broken above the critical field due to the quantum Stark effect. By applying electric fields, a sign reverse of g factors is observed, and an electric field tunable zero g factor is found in the quantum dot molecules. Spin-orbit interactions nicely explain the transition mechanism of g factors under external electric fields.