Transport measurements in Porous Bi<sub>2</sub>Te<sub>3</sub> thin films
ORAL
Abstract
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 Bi2Te3, with an increased surface to volume ratio, exhibits 2D-like transport.
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 Bi2Te3, with an increased surface to volume ratio, exhibits 2D-like transport.
*Australian Research Council Centre for Excellence Future Low Energy Electronics Technologies (CE170100039)
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Publication: [1] A. Agarwala, Topological insulators in amorphous systems, Excursions in Ill-Condensed Quantum Matter, Springer2019, pp. 61-79.
[2] M. Costa, G.R. Schleder, M. Buongiorno Nardelli, C. Lewenkopf, A. Fazzio, Toward realistic amorphous topological insulators, Nano letters, 19 (2019) 8941-8946.
[3] P. Adroguer, W.E. Liu, D. Culcer, E. Hankiewicz, Conductivity corrections for topological insulators with spin-orbit impurities: Hikami-Larkin-Nagaoka formula revisited, Physical Review B, 92 (2015) 241402.
Presenters
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Golrokh Akhgar
- Monash University