**Advancing quantum materials through first principles modeling**

Dr. Kateryna Foyevtsova

Senior Scientist

Research Associate

Stewart Blusson Quantum Matter Institute

The University of British Columbia | Vancouver

Quantum matter research, with its numerous intersections with materials and quantum information sciences, stands as one of the most rapidly advancing fields in modern physics. Quantum materials, i.e., materials in which emergent phenomena, such as magnetism or superconductivity, cause macroscopic quantum phenomena, are at the heart of modern switches, sensors, and energy technologies. In this talk, I will explore practical approaches to advance quantum matter research, where theory and experiment complement and guide each other in a synergistic way. Using the phenomenon of high-transition-temperature (high-T c ) superconductivity 1 as an illustration, I will showcase the power of theoretical insight and, in particular, of first principles modeling with methods based on Density Functional Theory 2 (DFT). To this end, I will focus on the recently discovered Ni-based high-T c superconductor Nd x Sr 1- x NiO 2 3 , for which I use DFT band structure calculations to identify the electronic degrees of freedom that are most relevant for the system’s low-energy physics 4 . One of the most surprising discoveries of this study is the strong electridelike properties exhibited by the parent compounds (i.e., NdNiO 2 ), which, contrary to initial expectations, make the nickelates rather distinct from the structurally and electronically similar Cu-based superconductors.

1. Bednorz & Muelle, Z. Phys. B. 64 (2): 189–193 (1986).

2. Hohenberg & Kohn, Physical Review. 136 (3B): B864–B871 (1964).

3. Li et al., Nature 572, 624–627 (2019).

4. Foyevtsova, Elfimov, Sawatzky, Phys. Rev. B 108, 205124 (2023).

*Hosted by Prof. Stepanov*