Multiscale simulation of phase change memory

This PhD thesis investigates the phase change material (PCM) based memory technology using multiscale theoretical modeling and numerical simulation. The multiscale analysis consists of three hierarchical parts: (i) the macroscopic simulation (about tens to hundres of nm and beyond), which studies the electro-thermal transport by using analytic derivation and time-dependent finite element method (TD-FEM); (ii) the mesoscopic simulation (about 1 to 10 nm), which investigates the electron transport properties by using the non-equilibrium Green's function (NEGF) method; and (iii) the microscopic simulation (about 0.1 to 1 nm), which studies the electronic structure, amorphization and crystallization processes by using density functional theory (DFT) and ab-initio molecular dynamics (AIMD).