סמינר בחומר מעובה: Dynamical mean-field theory approach to magnetic and charge correlations in low-dimensional systems

I review recent applications of the non-local extensions of dynamical mean-field theory approach (DMFT) to the low-dimensional systems possessing strong magnetic and/or charge correlations. These extensions are based on the possibility of calculation of non-local charge and spin susceptibilities using Bethe-Salpeter equations and consider self-energy and local vertices, irreducible in the particle-hole channel, extracted from DMFT. They also account for corrections extending the results beyond the finite Matsubara frequency range. As applications of this method, I consider suppression of antiferromagnetic order in the doped Mott insulator, charge and spin correlations in single- and twisted bilayer graphene, and exchange interactions in single-layer ferromagnetic systems. I show that the non-local extensions of DMFT allow to obtain valuable information on magnetic and charge properties of these systems.