Accelerating Nonequilibrium Green functions simulations with embedding selfenergies

Abstract

Real-time nonequilibrium Green functions (NEGF) have been very successful to simulate the dynamics of correlated many-particle systems far from equilibrium. However, NEGF simulations are computationally expensive since the effort scales cubically with the simulation duration. Recently we have introduced the G1--G2 scheme that allows for a dramatic reduction to time-linear scaling [Schlünzen, Phys. Rev. Lett. 124, 076601 (2020); Joost et al., Phys. Rev. B 101, 245101 (2020)]. Here we tackle another problem: the rapid growth of the computational effort with the system size. In many situations where the system of interest is coupled to a bath, to electric contacts or similar macroscopic systems for which a microscopic resolution of the electronic properties is not necessary, efficient simplifications are possible. This is achieved by the introduction of an embedding selfenergy -- a concept that has been successful in standard NEGF simulations. Here, we demonstrate how the embedding concept can be introduced into the G1--G2 scheme, allowing us to drastically accelerate NEGF embedding simulations. The approach is compatible with all advanced selfenergies that can be represented by the G1--G2 scheme [as described in Joost et al., Phys. Rev. B 105, 165155 (2022)] and retains the memory-less structure of the equations and their time linear scaling. As a numerical illustration we investigate the charge transfer between a Hubbard nanocluster and an additional site which is of relevance for the neutralization of ions in matter.

References in corpus (30)

• Hubbard model physics in transition metal dichalcogenide moiré bands
• Observation of Wigner crystal of electrons in a monolayer semiconductor
• Achieving the Ultimate Scaling Limit for Nonequilibrium Green Functions Simulations
• Time-dependent restricted active space Configuration Interaction for the photoionization of many-electron atoms
• Nonequilibrium dynamics in the one-dimensional Fermi-Hubbard model: A comparison of the nonequilibrium Green functions approach and the density matrix renormalization group method
• Hubbard nanoclusters far from equilibrium
• Fast Green's function method for ultrafast electron-boson dynamics
• First-principles nonequilibrium Green's function approach to transient photoabsorption: Application to atoms
• Real-time GW: Toward an ab initio description of the ultrafast carrier and exciton dynamics in two-dimensional materials
• The G1--G2 Scheme: Dramatic Acceleration of Nonequilibrium Green Functions Simulations Within the Hartree--Fock-GKBA
• Ab initio transport results for strongly correlated fermions
• Towards an integrated modeling of the plasma-solid interface
• Ultrafast Dynamics of Strongly Correlated Fermions -- Nonequilibrium Green Functions and Selfenergy Approximations
• Comparing the generalized Kadanoff-Baym ansatz with the full Kadanoff-Baym equations for an excitonic insulator out of equilibrium
• Quantum distillation and confinement of vacancies in a doublon sea
• Correlation effects in bistability at the nanoscale: steady state and beyond
• Accurate high-harmonic spectra from time-dependent two-particle reduced density matrix theory
• The dynamically screened ladder approximation: Simultaneous treatment of strong electronic correlations and dynamical screening out of equilibrium
• A many-body approach to transport in quantum systems: From the transient regime to the stationary state
• Photoinduced dynamics of organic molecules using nonequilibrium Green's functions with second-Born, $GW$, $T$-matrix and three-particle ladder correlations
• Shock Physics in Warm Dense Matter--a quantum hydrodynamics perspective
• Real-time dynamics of Auger wavepackets and decays in ultrafast charge migration processes
• Green's functions perspective on nonequilibrium thermodynamics of open quantum systems strongly coupled to baths
• Steady state conductance in a double quantum dot array: The nonequilibrium equation-of-motion Green function approach
• Nonequilibrium density matrix for simultaneous heat and charge steady-state transport in quantum open systems
• Time Reversal Invariance of quantum kinetic equations II: Density operator formalism
• Quantum fluctuations approach to the nonequilibrium $GW$ approximation
• Neutralization dynamics of slow highly charged ions passing through graphene nanoflakes--an embedding self-energy approach
• Invariant embedding approach to secondary electron emission from metals
• Light-field control of real and virtual charge carriers

Cited by in corpus (6)

• Accelerating Nonequilibrium Green functions simulations: the G1-G2 scheme and beyond
• 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
• Thermoelectric energy conversion in molecular junctions out of equilibrium
• Microscopic theory of current-induced skyrmion transport and its application in disordered spin textures
• Stability bounds for the generalized Kadanoff-Baym ansatz in the Holstein dimer