Transport measurements in Porous Bi₂Te₃ thin films

Recent theoretical work has predicted the existence of disordered topological insulators [1, 2], however, minimal experimental work has been conducted on disordered TIs. Here we used molecular-beam epitaxy (MBE) to grow Bi₂Te₃ thin films that were comprised of nanocrystals embedded in an amorphous matrix. Further disorder was introduced through Ne ion irradiation which produced porosity in the films.

In this talk we will present magnetoresistance measurements on porous Bi₂Te₃, where weak anti-localisation (WAL) was observed. The magnetoresistance curves were fitted using a Dirac Fermion model specifically derived to model weak antilocalization in TIs [3]. Our results also show that the temperature dependence of the phase coherence length in porous Bi₂Te_3, with an increased surface to volume ratio, exhibits 2D-like transport.