Magnetoresistance Measurements of Polycrystalline and Amorphous Bi2Te3 Thin Films

PhD Candidate, Monash University

Crystalline topological insulators have been on the forefront of condensed matter research for the past decade. However, disordered topological insulators have not been examined in much detail since current models of topological insulators rely heavily on the materials’ electronic band structure. Without the translational symmetries necessary to create a well-defined reciprocal space disordered materials have long been presumed to not exhibit topological properties. However, very recent theoretical models have predicted the existence of topologically protected states in disordered materials. This poster will present temperature dependent magnetoresistance, Hall effect, and temperature dependent resistivity measurements of polycrystalline and amorphous Bi₂Te₃ thin films. These early results suggest the materials exhibit weak anti-localization.

About the presenter

Alexander Nguyen is a materials engineer working with Dr Julie Karel at Monash University, where he performs magnetoelectronic transport measurements on amorphous topological insulators within FLEET’s research theme 1 and enabling technology B. An important aim is to experimentally realise topologically-protected states in an amorphous material, which may offer some benefits over crystalline materials. 

Another major career focus for Alexander is improving diversity in academia, especially in STEM. He is a queer officer for the Monash Graduate Association, has helped organise events supporting queer graduates at Monash, and recently became a member of the first Diversity & Inclusion Committee in the Monash Material Science and Engineering department.