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PGI Kolloquium: Prof. Dr. Oleg Yazyev, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland

Online Talk

Please note: You will receive the link to the online talk in the e-mail invitation, usually sent out a few days before the lecture takes place. It is also available on request from the contact person below.

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05.11.2021 11:00 Uhr

In silico discovery of novel topological materials 

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In my talk, I will focus on our recent efforts directed towards the search of novel topological materials. A large number of diverse topological electronic phases that can be realized in materials have been predicted recently. We have developed a high-throughput computational screening methodology for identifying materials hosting various topological phases among known materials.

The entire dataset of results obtained using this high-throughput search is now publicly available via the Materials Cloud platform [1]. Several predictions resulting from this search that have been successfully confirmed by experiments. A new Z2 topological insulator was theoretically predicted and experimentally confirmed in the β-phase of quasi-one-dimensional bismuth iodide Bi4I4 [2]. The electronic structure of β-Bi4I4, characterized by Z2 invariants (1;110), is in proximity of both the weak TI phase (0;001) and the trivial insulator phase (0;000).

We further predicted robust type-II Weyl semimetal phase in transition metal diphosphides MoP2 and WP2 characterized by very large momentum-space separation between Weyl points of opposite chirality [3]. Recent experiments on WP2 revealed record magnitudes of magnetoresistance combined with very high conductivity and residual resistivity ratio [4], and many other extraordinary properties. I will discuss in detail the physical mechanism underlying magnetotransport in WP2 as well as in other trivial and topological semimetals [5].

 

[1] G. Autès, Q. S. Wu, N. Mounet, and O. V. Yazyev, “TopoMat: a database of high-throughput first-principles calculations of topological materials”, https://www.materialscloud.org/discover/topomat

[2] G. Autès et al., Nature Mater. 15, 154 (2016).

[3] G. Autès, D. Gresch, M. Troyer, A. A. Soluyanov and O. V. Yazyev, Phys. Rev. Lett. 117, 066402 (2016).

[4] N. Kumar et al., Nature Commun. 8, 1642 (2017).

[5] S. N. Zhang, Q. S. Wu, Y. Liu and O. V. Yazyev, Phys. Rev. B 99, 035142 (2019).

Kontakt

Dr. Gustav Bihlmayer
Telefon: +49 2461 61-4677
Fax: +49 2461 61-2850
E-Mail: g.bihlmayer@fz-juelich.de