Quantum Mechanical Simulation of Polarization Switching in HfO2 Crystals.

Int this paper, we study the process of changing the polarization of hafnium oxide crystals in the orthorhombic phase associated with the gradual weakening of polarization effects in FeRAM elements based on thin films of hafnium oxide HfO2. To solve the problem, quantum mechanical calculations of the structure of orthorhombic hafnium oxide are performed, a possible way of crystal restructuring during a change in polarization when a voltage is applied is identified, and its optimization is carried out using the elastic band method. The values of the change in polarization and the energy barrier of the corresponding transition are obtained. The stability of this transition is studied. The results of a series of computational experiments using high-performance computing systems of hybrid architecture based on the Center for Collective Use at the Federal Research Center "Computer Science and Control" are presented. An analysis of the results shows that, despite the low energy barrier of the transition, the probability of a spontaneous change in polarization is low due to the impossibility of changing the polarization of an individual cell with no allowance for the effect of the polarizations of the neighboring cells. [ABSTRACT FROM AUTHOR]