Exploratory topological semimetal materials for Beyond CMOS devices

​Topological materials such as topological insulators or topological Dirac and Weyl semimetals form a new and exciting material class in condensed matter physics. Their unique band structure gives rise to unusual electronic properties and behavior in magnetic and electrical fields with high potential relevance for future applications in spintronics and quantum computing.

This PhD project focuses on topological Dirac semimetals, which are often considered as a 3D analogue of graphene due to their bulk band structure with Dirac points and gap-less linear dispersion in all three momentum directions. So far, the number of reported topological Dirac semimetals is limited (examples include Na3Bi, Cd3As2, Bi1-xSbx) and they have been studied mostly in bulk single crystals or in single crystal flakes. Not only is it of utmost importance to search for more and better topological material realizations, but it is also highly needed to control the production of topological semimetal thin films and nanostructures in order to integrate the unique properties into devices and combine these materials into heterostructures with different functionalities. 

In this project we aim to develop a novel highly controllable epitaxial topological semimetal based on the orthorhombic phase of SrIrO3.  This material is compatible with thin film epitaxial growth technology and nanodevice fabrication. Moreover, of particular fundamental interest is the recent theoretical prediction that this material can be tuned between different topological semimetal phases by application of a magnetic field along specific crystal orientations. [Y. Chen et al., Nature Comm. 6, 6593 (2015)]. Such complex metal oxide system is of very high interest due to the possible combination with other ferromagnetic or superconducting perovskite oxides that can be easily co-integrated with epitaxial sharp interfaces. Recently, orthorhombic SrIrO3 has shown strong advantages in the field of room temperature and low power spintronic applications.

This PhD project involves experimental research with a focus on thin film growth and structural and electrical characterization, using state-of-the-art molecular beam epitaxy systems and characterization techniques as well as magneto-transport experiments at low temperatures and high magnetic fields and their in-depth analysis based on physical models. 

KU Leuven supervisor: Margriet Van Bael (KU Leuven)
Location: Leuven
Focus of work: Materials; Devices

The reference code of this topic is 2021-054. Please mention this on your application.

The next application window will be open from mid-March 2021 until mid-April 2021.
It is not possible to send in your application before mid-March 2021.