Fig: The weak antilocalization response in stacked heterostructures consisting of 3D topological insulators (TI) and trivial insulators (NI) can be used to access the phase diagrams of these artificial quantum systems [2].

The discovery of topological materials in the end of the 2000s has substantially changed the perspective of  condensed matter physicists. With the importance of the topology of wave functions within the Brillouin being recognized, multiple classic questions of  condensed matter physics had to be reconsidered. Amongst them is the question of Anderson localization.

In my research [1] during my PhD, I investigated the impact of impurities and intermediately strong electron-electron interactions on the surface states of 3D topological insulators. 

Using this experience, in a joint theory-experiment effort [2], we have recently been able to extract phase diagrams of topological insulator heterostructures by carefully analyzing their weak anti-localization data. Our research proves the possibility of building artifical 3D Dirac and Weyl semimetallic structures by means of "van-der-Waals LEGO".

[1] EJ König, et al. Phys. Rev. B 85, 195130 (2012), Phys. Rev. B 88, 035106 (2013), Phys. Rev. B 90, 165435 (2014)
[2] PP Shibayev*, EJ König*, M Salehi, J Moon, M-G Han, S Oh, Nano Lett. 19 (2) 716-721 (2019)