This paper proposes a double barrier design for ferroelectric tunnel junctions (FTJs) to enhance tunneling electroresistance (TER). A Pt/BaTiO3/LaAlO3/Pt/BaTiO3/LaAlO3/Pt double barrier FTJ (DB-FTJ) model is designed and studied using density functional calculations. The DB-FTJ exhibits a giant TER ratio of 2.210 × 10⁶, significantly larger than single barrier FTJs. It also features an ultra-low resistance area product (0.093 kΩµm²) in the high conductance state. Independent polarization control of the two barriers allows for four resistance states, making DB-FTJs promising for multi-state memory applications.
