Interfacial phase change memory (iPCM) is magnetic sensitive at room temperature while the alloy with same composition is not. The unique property has been thought to be related to the topological insulating property. We discuss the magnetic properties on the point of view of the spatial inversion symmetry of iPCM structures and ferroelectricity of GeTe layers sandwiched by topological insulati...

We use convergence theory as the framework for studying Hclosed spaces and H-sets in topological spaces. From this viewpoint, it becomes clear that the property of being H-closed and the property of being an H-set in a topological space are pretopological notions. Additionally, we define a version of H-closedness for pretopological spaces and investigate the properties of such a space.