Quantum Algorithms to Improve Density Functional Theory

Density functional theory (DFT) struggles to accurately describe strong electron correlations. To address this limitation, we develop a hybrid quantum-classical approach that computes spin-dependent exchange-correlation (XC) potential using variational quantum circuits. The method is tested on the one- and two-dimensional Hubbard model, where it accurately reproduces exact ground-state energies and XC potentials for various interaction strengths. Our results demonstrate that this approach can systematically capture correlation effects beyond standard approximations, paving the way for scalable methods for strongly correlated systems.