We are hiring a PhD student fully-funded by the Lindsay Trust to work on electronic structure theory for futuristic oxide electronics materials. The project is supervised by PI Dr. Hrishit Banerjee (co-supervised by Dr. Andrei Pisliakov). The student will be based at the School of Science and Engineering, University of Dundee, Scotland, UK.

Project Description:

The study of complex oxides and oxide heterostructures have dominated the field of experimental and theoretical condensed matter research in the last few decades. Advanced experimental techniques have made fabrication of sharp oxide heterostructures possible. The emergence of a high mobility 2D electron gas with fascinating properties like giant photoconductance, large negative magnetoresistance, superconductivity, ferromagnetism, and coexistence of latter two have caught the attention of condensed matter community. Theoretical understanding of most of these phenomena are lacking. Strain tuning of oxides have also garnered interest mainly after the recent discovery of piezoelectric methods of strain generation. Theoretical explanation and prediction of the possible exotic phases emerging in complex oxides both under strain and in heterostructures will lead to better design & control of device applications and usher in the era of low power energy efficient “oxide electronics”!

The primary objective of this research project is to understand the role of correlations in various oxides under strain and oxide heterostructures in giving rise to novel states. First, we explore the effect of biaxial and uniaxial strain on bulk oxides to gain an understanding of their strain tuning. We plan to study strain effects on correlated oxides. Strain induced properties viz. ferroelectricity, tuning of bandwidths, crystal field splitting, structural & electronic phase transitions leading to various novel states, unconventional metal insulator (M I) transitions etc shall be studied. Next, we focus on oxide heterostructures & the interface 2D electron gas. Exotic phases like spin orbit coupled states, giant magnetoresistance, temperature dependent M-I transitions, correlation driven magnetic transitions, anomalous hall effect etc will be addressed in several systems. We intend to develop a method to carry out structural relaxations using dynamical mean-field theory (DMFT) which is imperative to understand interplay of structural effects and strong correlations. Finally using these developed methods and the understanding gained by studying various oxide heterostructure system, we shall tackle the very complex and puzzling problem of co-existence of ferromagnetism and superconductivity in some specific oxide heterostructures like LaTiO3/SrTiO3.

The primary method of calculation shall be ab initio DMFT modelling. Using density functional theory (DFT) interaction parameters as input, DMFT calculations shall include the effects of strong correlations. Toolbox for research in interacting Quantum Systems (TRIQS) code shall be used for DMFT calculations, with Continuous time Quantum Monte Carlo Solvers in hybridisation expansion (CT-Hyb) or other solvers. Specialised solvers like Fork Tensor Product State (FTPS) solvers will be used for studies on superconductivity at very low temperatures.

The project is envisaged as highly original and new work tackling questions of very complex nature requiring innovative methods of solution. The systems studied experimentally have little or no theoretical understanding. Strain tuning of oxides shall be suggested with possible emergence of probable exotic states and its applications. New heterostructures with possible growth conditions shall be suggested & theoretical understanding of existing novel phenomena proffered, leading to better design and control of properties.

Link for Application can be found here:

https://www.dundee.ac.uk/phds/projects/exotic-phases-oxides-under-strain-and-oxide-heterostructures

Details of Lindsay Trust scholarship can be found here:

https://www.dundee.ac.uk/phds/funding/en-mn-lindsay-scholarship

Deadline for Application: 29th March 2024

Informal queries can be directed to Dr. Hrishit Banerjee ([email protected])