Unveiling the Non-Equilibrium Energetics of Ferroelectric Tunnel Junctions with Multi-Space Density Functional Theory

Ferroelectric tunnel junctions (FTJs) have gained considerable attention for their scientific merits as well as application potential for memory technology. However, employing a first-principles approach to reveal their characteristics in non-equilibrium conditions remains a largely unexplored domain. Utilizing our newly developed multi-space constrained-search density functional theory (MS-DFT) formalism [1-3], we have been exploring FTJs based on perovskite oxides [4] and 2D CuInP₂S₆ [5]. In this presentation, we describe an updated methodological and analysis framework for FTJs based on the electric enthalpy concept. Specifically, the free energy and C-V profiles as well as the current-voltage characteristics will be discussed for the above-mentioned capacitor models.

References:

1. 1. K. Rajput, R. G. Lee, T. H. Kim, H. Yeo, J. Lee & Y. –H. Kim, Bulletin of the American Physical Society (2023).
   
   2. Y. Song, J. Lee, & Y.-H. Kim, APS March Meeting Abstracts., 2021, H71-220, (2021).
   
   3. J. Lee, H. S. Kim, & Y.-H. Kim, Adv. Sci., 7, 2001038 (2020).
   
   4. J. Lee, H. Yeo, & Y.-H. Kim, Proc. .Nat. Acad. Sci., 117, 10142 (2020).
   
   5. T. H. Kim, J. Lee, R. G. Lee, & Y.-H. Kim, npj Comput Mater 8, 50 (2022).