PhD - Leuven | More than two weeks ago
Topological materials, such as topological insulators (TI) or Weyls semimetals, are a novel class of materials featuring intriguing new quantum states of matters and properties. The appearance of topologically protected states at the edges of 2D nanoribbons made of TI materials (such as stanene or bismuthene) in proximity of superconducting (SC) materials may allow for the observation of the long predicted Majorana Fermions. Owing to their long coherence time, Majorana states in TI are considered as very promising candidates to build quantum bits (qbits), the basic blocks to build a quantum computer. Topological materials can be used under certain conditions to enable spin-polarized transport which is interesting for spintronics. Besides being used in conjunction with TI to induce Majorana Fermions, SC materials also have direct applications, like in Josephson-Junction used for quantum computing. In addition, the emergence of superconductivity in 2D materials has attracted much attention and there has been rapid development in recent years because of their fruitful physical properties, such as high transition temperature, continuous phase transition, and enhanced parallel critical magnetic field.
In this thesis, you will explore the transport properties of innovative devices made of topological and superconducting 2D materials, including edge functionalization or the application of electrical and magnetic fields to study and tune their properties, using a blend of density functional theory (DFT) methods (Quantum Espresso, CP2K, OPENMX) and advanced ab-initio quantum transport (NEGF) simulations (Atomos) [1-4], with as possible target applications, quantum computing or spintronics. You will learn and benefit from the support from modeling experts in the field. The possibility to interact with experimentalists is also available at imec.
 Afzalian, A. Ab initio perspective of ultra-scaled CMOS from 2D-material fundamentals to dynamically doped transistors. npj 2D Mater Appl 5, 5 (2021). https://www.nature.com/articles/s41699-020-00181-1
 A. Afzalian, E. Akhoundi G. Gaddemane, R. Duflou and M. Houssa, "Advanced DFT–NEGF Transport Techniques for Novel 2-D Material and Device Exploration Including HfS2/WSe2 van der Waals Heterojunction TFET and WTe2/WS2 Metal/Semiconductor Contact," in IEEE Transactions on Electron Devices, vol. 68, no. 11, pp. 5372-5379, Nov. 2021, doi: 10.1109/TED.2021.3078412 (invited)
 E. Akhoundi, M. Houssa, A. Afzalian, The impact of electron phonon scattering on transport properties of topological insulators: A first principles quantum transport study, Solid-State Electronics (SI: LETTERS from the International Conference on Simulation of Semiconductor Processes and Devices 2022), 201, 108587 (2023). https://doi.org/10.1016/j.sse.2022.108587.
 E. Akhoundi, M. Houssa, A. Afzalian, The Impact of Electron Phonon Scattering, Finite Size and Lateral Electric Field on Transport Properties of Topological Insulators: A First Principles Quantum Transport Study: a first principles quantum transport study, Materials 2023, 16(4), 1603; https://doi.org/10.3390/ma16041603.
Required background: Physical/Electrical/Electronic/Material Engineering, Physics or Chemistry
Type of work: ~50% NEGF device simulations, ~30% DFT material simulation, ~20% quantum transport code development
Supervisor: Michel Houssa
Co-supervisor: Aryan Afzalian
Daily advisor: Aryan Afzalian
The reference code for this position is 2024-027. Mention this reference code on your application form.