Abstract
Motivated by recent experiments on heterostructures, we study the temperature dependent screening effects on the surface of a three-dimensional topological insulator proximate to a ferromagnetically ordered system. In general, we find that besides the chemical potential and temperature, the screening energy scale also depends on the proximity-induced electronic gap in an essential way. In particular, at zero temperature the screening energy vanishes if the chemical potential is smaller than the proximity-induced electronic gap. We show that at finite temperature and/or chemical potential , the Chern-Simons (topological) mass, which is generated by quantum fluctuations arising from the proximity effect, can be calculated analytically in the insulating regime. In this case the topological mass yields the Hall conductivity associated with edge states. We show that when the chemical potential is inside the gap the topological mass remains nearly quantized at finite temperature.
- Received 16 September 2013
- Revised 15 July 2014
DOI:https://doi.org/10.1103/PhysRevB.90.014431
©2014 American Physical Society