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 . In this Letter, 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.
- Received 16 April 2010
DOI:https://doi.org/10.1103/PhysRevLett.105.166803
© 2010 The American Physical Society
Synopsis
Fundamental constants from topological insulators
Published 13 October 2010
Measuring the quantized magnetoelectric response in topological insulators could help establish precise values for basic physical constants.
See more in Physics