Join the Quantum Matter group in a seminar titled "Going beyond density functional theory to understand the electron correlation effects" by Dr. Alyn James.
Date: 7th July 2023, 2:00PM - 3:00PM
Location: Frank Lecture Theatre, Physics Building
Abstract:
Density functional theory (DFT) has been widely used and is often adequate for certain characteristics of weakly correlated materials, such as the Fermi surface of Cu. However, when probing materials with significant electron correlation effects and considering improvements in both experimental resolution and statistical precision, the widely used approximations for the DFT exchange-correlation functional are no longer sufficient. One way to improve the description of electron correlations, especially where these types of correlations are important, such as the Mott metal-insulator transition (MIT) [1], is to include local electron correlations from dynamical mean field theory with DFT (the so-called DFT+DMFT method [2]).
In this seminar, I will discuss the technique of calculating the DFT+DMFT electron momentum density [3], along with comparisons to the experimental Compton scattering data of (weakly correlated) ferromagnetic Ni [3] and (strongly correlated) paramagnetic delafossite PdCrO2 [4]. Furthermore, the origin of the measured doping-dependent MIT in the substitutionally doped SrTi1-xVxO3 [5, 6] will be discussed from the DFT+DMFT perspective. Understanding the unique viewpoint that DFT+DMFT offers in comparison with the experimental data is important for gaining a deeper insight into the nature of the correlation effects within the electronic structure.