Epitaxial thin films and heterostructures of chiral topological semimetals
The quantum materials with nontrivial topology have come to the forefront of solid-state research as candidate materials including catalysis, low-power electronics, high-performance optoelectronic devices and topological quantum computing. The development of topological chiral crystals immediately led to the groundbreaking prediction and experimental realization of multifold semimetals in the nonmagnetic B20 family of materials. These materials possess chirality in momentum space in addition to their chirality in crystal structure with high Chern numbers [1-4]. This leads to several remarkable properties, including a giant quantized circular photogalvanic current, a chiral magnetic effect, and other transport and optical effects which are forbidden in Weyl semimetals. Thin film growth would allow the control of the topological properties of these materials via film thickness, doping or strain, a parameter space that cannot be explored with the present bulk crystals. In thin films, the properties of the surface play a significant role due to the intrinsic topology nested in the electronic structure.
This project aims to study thin films and heterostructures of chiral topological semimetals in the B20 class of materials. The PhD candidate will use state-of-the-art facilities of the Max Planck Institute for the Chemical Physics of Solids in Dresden to grow high-quality epitaxial thin films by magnetron sputtering on single crystalline substrates. The effects of the composition and the interfaces with other quantum materials, e.g., topological materials, ferromagnets, and superconductors, will be studied as well. By studying their magnetic and electrical transport properties, it should be possible to obtain fundamental insights into their topologically driven physical effects, whilst allowing the application of these materials to be extended into functional devices. In addition, some experiments will be performed in collaboration with the Technical University of Dresden.
The PhD candidate should have an excellent understanding of solid-state physics and materials science and be motivated to work in a highly collaborative research environment.