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arXiv · 1004.2514

Topological quantization in units of the fine structure constant

Joseph Maciejko·Xiao-Liang Qi·H. Dennis Drew·Shou-Cheng Zhang
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Abstract

Fundamental topological phenomena in condensed matter physics are associated with a quantized electromagnetic response in units of fundamental constants. Recently, it has been predicted theoretically that the time-reversal invariant topological insulator in three dimensions exhibits a topological magnetoelectric effect quantized in units of the fine structure constant $α=e^2/\hbar c$. In this work, we propose an optical experiment to directly measure this topological quantization phenomenon, independent of material details. Our proposal also provides a way to measure the half-quantized Hall conductances on the two surfaces of the topological insulator independently of each other.

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Joseph Maciejko, Xiao-Liang Qi, H. Dennis Drew, Shou-Cheng Zhang. 2010-10-12. Topological quantization in units of the fine structure constant. https://doi.org/10.1103/physrevlett.105.166803

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