Quantum simulation of structure switching in molecular system

This article presents the results of ab initio quantum simulation of graphite-like structure formation from amorphous carbon. Our work is devoted to explanation of resistance switching mechanism in experiments on phase-change memory. Here, we use two-scale molecular dynamics model, which consists of Car–Parrinello quantum molecular dynamics (CPMD) and modified Ehrenfest molecular dynamics. The results of simulation point the appearance of layered graphite-like molecular structure under temperature increase. These changes can be considered as a phase transition of second kind in nanostructured material, which leads to threshold resistance switching. For calculations, we used the IBM BlueGene/P supercomputer installed at the Faculty of Computational Mathematics and Cybernetics of the Moscow State University.