Real-frequency response functions at finite temperature

Abstract

Building on previous developments, we show that the Diagrammatic Monte Carlo technique allows to compute finite temperature response functions directly on the real-frequency axis within any field-theoretical formulation of the interacting fermion problem. There are no limitations on the type and nature of the system's action or whether partial summation and self-consistent treatment of certain diagram classes are used. In particular, by eliminating the need for numerical analytic continuation from a Matsubara representation, our scheme allows to study spectral densities of arbitrary complexity with controlled accuracy in models with frequency-dependent effective interactions. For illustrative purposes we consider the problem of the plasmon line-width in a homogeneous electron gas (jellium).

arXiv comment5 pages and 5 figures in the main text plus 7 pages and 7 figures in the Supplemental material

References in corpus (13)

• Controlling Feynman diagrammatic expansions: physical nature of the pseudo gap in the two-dimensional Hubbard model
• Numerical analytic continuation: Answers to well-posed questions
• Shifted-Action Expansion and Applicability of Dressed Diagrammatic Schemes
• Algorithmic Matsubara Integration for Hubbard-like models
• Polynomial complexity despite the fermionic sign
• Real-frequency Diagrammatic Monte Carlo at Finite Temperature
• Optimal grouping of arbitrary diagrammatic expansions via analytic pole structure
• Algorithmic approach to diagrammatic expansions for real-frequency evaluation of susceptibility functions
• Decay dynamics of Localised Surface Plasmons: damping of coherences and populations of the oscillatory plasmon modes
• Homotopic Action: A Pathway to Convergent Diagrammatic Theories
• Analytical solution for time-integrals in diagrammatic expansions: application to real-frequency diagrammatic Monte Carlo
• Dielectric function and thermodynamic properties of jellium in the GW approximation
• Signatures of multiple charge excitations in RIXS spectra of metals

Cited by in corpus (8)

• Dynamic Response of an Electron Gas: Towards the Exact Exchange-Correlation Kernel
• Single particle properties of the 2D Hubbard model for real frequencies at weak coupling: Breakdown of the Dyson series for partial self-energy expansions
• LIBAMI: Implementation of Algorithmic Matsubara Integration
• Renormalized Perturbation Theory for Fast Evaluation of Feynman Diagrams on the Real Frequency Axis
• One- and two-particle properties of the weakly interacting two-dimensional Hubbard model in proximity to the van Hove singularity
• Solving the Bethe-Salpeter Equation in Real Frequencies at Finite Temperature
• Physical and unphysical regimes of self-consistent many-body perturbation theory
• Automated evaluation of imaginary time strong coupling diagrams by sum-of-exponentials hybridization fitting