２０１９年１月３０日 Prof. Kuo-An Wu

日時：２０１９年１月３０日（水）　１１：００〜１２：３０
場所：首都大学東京　８号館３０２号室
講師：Prof. Kuo-An Wu (National Tsing Hua University)
題目：Pattern formation theory in tackling challenges in condensed matter at the nanoscale

要旨：The Swift-Hohenberg equation has been widely used to model formation of patterns seen in nonlinear systems at the macroscopic scale. The phenomenological model can be recast into an atomistic continuum model, namely the phase field crystal model, to describe material systems where the self-organized patterns represent crystal lattice structures. Besides its close relation to the Swift-Hohenberg equation, the phase field crystal approach has its roots in the classical density functional theory of freezing, and it bridges the molecular simulations and macroscopic continuum models. In this talk, I will briefly discuss how the lattice pattern at the atomistic scale naturally gives rise to anisotropies in surface energies and kinetic coefficients which are main determinants of morphology of crystals at the macroscopic scale. In addition, the simple phase field crystal model is capable of describing elasticity, plasticity, and discrete dislocations that enables us to study fundamental mechanisms of nanocrystalline grain growth and grain boundary grooving. I will discuss how discrete structures, such as dislocations and grain boundaries (usually omitted in classical theory), drastically change predictions of classical theory.