Īlthough the topological classification and the importance of time-reversal symmetry was pointed in the 2000s, all the necessary ingredients and physics of topological insulators were already understood in the works from the 1980s. The transport due to 1D helical edge states was indeed observed in the experiments by Molenkamp's group in 2007. Hughes and Zhang made a theoretical prediction that 2D topological insulator with one-dimensional (1D) helical edge states would be realized in quantum wells (very thin layers) of mercury telluride sandwiched between cadmium telluride.

The diagram depicts a Z 2 topological invariant was constructed and the importance of the time reversal symmetry was clarified in the work by Kane and Mele. There is no path from the topological insulators to the trivial insulators that does not cross the conducting phase. ( August 2016) ( Learn how and when to remove this template message)Īn (informal) phase diagram with topological insulators, trivial insulators, and conductors. Please help improve it to make it understandable to non-experts, without removing the technical details.

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