15 citations · 42 across the 11 of their papers we have counts for
7 papers · 1 filter
Hybrid Hamiltonian-diagrammatic quantum impurity solver
Yang Yu, Gaurav Harsha, Lei Zhang +4
Quantum impurity models, which describe the coupling between interacting orbitals and a non-interacting bath, play a central role in the physics of strongly correlated electron sys…
Multi-orbital dynamical mean-field theory with a complex-time solver
Yang Yu, Lei Zhang, Emanuel Gull +2
We present the combination of a complex-time tensor-network impurity solver with an analytic continuation scheme based on exponential fitting as an efficient framework for single a…
Compact representation and long-time extrapolation of real-time data for quantum systems using the ESPRIT algorithm
Andre Erpenbeck, Yuanran Zhu, Yang Yu +6
Representing real-time data as a sum of complex exponentials provides a compact form that enables both denoising and extrapolation. As a fully data-driven method, the Estimation of…
Minimal pole representation for spectral functions
Lei Zhang, André Erpenbeck, Yang Yu +1
Representing spectral densities, real-frequency, and real-time Green's functions of continuous systems by a small discrete set of complex poles is an ubiquitous problem in condense…
Minimal pole representation and analytic continuation of matrix-valued correlation functions
Lei Zhang, Yang Yu, Emanuel Gull
We present a minimal pole method for analytically continuing matrix-valued imaginary frequency correlation functions to the real axis, enabling precise access to off-diagonal eleme…
Feynman diagrammatics based on discrete pole representations: A path to renormalized perturbation theories
Daria Gazizova, Lei Zhang, Emanuel Gull +1
By merging algorithmic Matsubara integration with discrete pole representations we present a procedure to generate fully analytic closed form results for impurity problems at fixed…
Minimal Pole Representation and Controlled Analytic Continuation of Matsubara Response Functions
Lei Zhang, Emanuel Gull
Analytical continuation is a central step in the simulation of finite-temperature field theories in which numerically obtained Matsubara data is continued to the real frequency axi…