Density matrix embedding theory for multi-band models and ab initio materials*

Accurate description of correlated materials remains an essential challenge in the condensed matter physics. Quantum embedding theory provides an economical way to treat large system with local information from small fragments. In this work, we will discuss the formulation of density matrix embedding theory (DMET) for both multi-band lattice models and ab initio solids, with an emphasize on the unified framework and its efficient implementation. We applied DMET to the three-band Hubbard model to study the magnetic and superconducting ground-state phase diagram of high-T_c cuprates. We also benchmarked the ab initio DMET by calculating energy, equation-of-state and spin correlation function of realistic materials (h-BN, Si and NiO) with large embedding cluster up to 300 orbitals.

Reference:
Z.-H. Cui, C. Sun, U. Ray, B.-X. Zheng, Q. Sun, G. K.-L. Chan, Phys. Rev. Res. arXiv:2001.04951 (2020).
Z.-H. Cui, T. Zhu, G. K.-L. Chan, J. Chem. Theory Comput., 16, 119 (2020).