Topological Insulators: Donuts, Coffee Cups And Soundproofing With Quantum Physics
Donuts, electric current and quantum physics - if you are a theoretical physicist interested in topological insulators, materials whose ability to conduct electric current originates in their topology, it makes perfect sense. The easiest way to understand what "topological" means in this context is to imagine how a donut can be turned into a coffee cup by pulling, stretching and moulding - but without cutting it. Topologically speaking, therefore, doughnuts and coffee cups are identical, and by applying the same principle to the quantum mechanical wave function of electrons in a solid one obtains the phenomenon of the topological insulator. This is advanced quantum physics, highly complex and far removed from everyday experience. read more