The dynamically screened ladder approximation: Simultaneous treatment of strong electronic correlations and dynamical screening out of equilibrium

Abstract

Dynamical screening is a key property of charged many-particle systems. Its theoretical description is based on the $GW$ approximation that is extensively applied for ground-state and equilibrium situations but also for systems driven out of equilibrium. The main limitation of the $GW$ approximation is the neglect of strong electronic correlation effects that are important in many materials as well as in dense plasmas. Here we derive the dynamically screened ladder (DSL) approximation that selfconsistently includes, in addition to the $GW$ diagrams, also particle--particle and particle--hole $T$-matrix diagrams. The derivation is based on reduced-density-operator theory and the result is equivalent to the recently presented G1--G2 scheme [Schlünzen \textit{et al.}, Phys. Rev. Lett. \textbf{124}, 076601 (2020); Joost \textit{et al.}, Phys. Rev. B \textbf{101}, 245101 (2020)]. We perform extensive time-dependent DSL simulations for finite Hubbard clusters and present tests against exact results that confirm excellent accuracy as well as total energy conservation of the approximation. At strong coupling and for long simulation durations, instabilities are observed. These problems are solved by enforcing contraction consistency and applying a purification approach.

References in corpus (7)

• Interaction Quench in the Hubbard model
• Real-time GW: Toward an ab initio description of the ultrafast carrier and exciton dynamics in two-dimensional materials
• Diagrammatic expansion for positive spectral functions beyond GW: Application to vertex corrections in the electron gas
• Propagating two-particle reduced density matrices without wavefunctions
• Challenges in Truncating the Hierarchy of Time-Dependent Reduced Density Matrices Equations: Open Problems
• Accurate high-harmonic spectra from time-dependent two-particle reduced density matrix theory
• Diagrammatic expansion for positive density-response spectra: Application to the electron gas

Cited by in corpus (20)

• Electronic Density Response of Warm Dense Matter
• First principles simulations of dense hydrogen
• Dynamic Mode Decomposition for Extrapolating Non-equilibrium Green's Functions Dynamics
• Non-equilibrium correlation dynamics in the one-dimensional Fermi-Hubbard model: A testbed for the two-particle reduced density matrix theory
• Accelerating Nonequilibrium Green functions simulations: the G1-G2 scheme and beyond
• Quantum fluctuations approach to the nonequilibrium $GW$ approximation
• Ionization potential depression and Fermi barrier in warm dense matter--a first--principles approach
• Accelerating Nonequilibrium Green functions simulations with embedding selfenergies
• Electroluminescence rectification and high harmonic generation in molecular junctions
• Classical and Quantum Theory of Fluctuations for Many-Particle Systems out of Equilibrium
• Quantum Fluctuations Approach to the Nonequilibrium $GW$-Approximation II: Density Correlations and Dynamic Structure Factor
• Two-Time Quantum Fluctuations Approach and its Relation to the Bethe--Salpeter Equation
• Interacting electrons in a flat-band system within the Generalized Kadanoff-Baym Ansatz
• Ultrafast Charge Separation Induced by a Uniform Field in Graphene Nanoribbons
• Mean-field approximation of the Hubbard model expressed in a many-body basis
• A causality-based divide-and-conquer algorithm for nonequilibrium Green's function calculations with quantics tensor trains
• Stability bounds for the generalized Kadanoff-Baym ansatz in the Holstein dimer
• Non-Markovian quantum kinetic simulations of uniform dense plasmas: mitigating the aliasing problem
• Capturing reduced-order quantum many-body dynamics out of equilibrium via neural ordinary differential equations
• Fermionic-propagator and alternating-basis quantum Monte Carlo methods for correlated electrons on a lattice