Magnetization switching by combining electric field and spin-transfer torque effects in a perpendicular magnetic tunnel junction

Effective manipulation of magnetization orientation driven by electric field in a perpendicularly magnetized tunnel junction introduces technologically relevant possibility for developing low power magnetic memories. However, the bipolar orientation characteristic of toggle-like magnetization switching possesses intrinsic difficulties for practical applications. By including both the in-plane (T _∥) and field-like (T_⊥) spin-transfer torque terms in the Landau-Lifshitz-Gilbert simulation, reliable and deterministic magnetization reversal can be achieved at a significantly reduced current density of 5×10⁹ A/m² under the co-action of electric field and spin-polarized current, provided that the electric-field pulse duration exceeds a certain critical value τ_c. The required critical τ_c decreases with the increase of T_⊥ strength because stronger T_⊥ can make the finally stabilized out-of-plane component of magnetization stay in a larger negative value. The power consumption for such kind of deterministic magnetization switching is found to be two orders of magnitude lower than that of the switching driven by current only.