Real-Frequency DMFT Calculations Using Tensor Network Methods implemented complex time evolution

Recently, there has been a growing trend of utilizing Density Matrix Renormalization Group (DMRG) as an impurity solver capable of performing calculations on the real-frequency axis within the Dynamical Mean Field Theory (DMFT) framework. The fast growth of entanglement entropy in real-time evolution has been a bottleneck for the application of DMRG in dynamic systems, which has been partially resolved by a recently proposed complex-time evolution scheme. In this study, we present our recent results on single impurity DMFT calculations using a complex-time evolution DMRG solver, especially focusing on the evolution of the zero-temperature spectral function A(k, ω) as a function of U/W on a two-dimensional square lattice. Furthermore, we explore the potential of performing DMFT calculations in two-orbital and three-orbital systems using the fork tensor network method .