TY - JOUR

T1 - A Scalable Numerical Approach to the Solution of the Dyson Equation for the Non-Equilibrium Single-Particle Green's Function

AU - Talarico, Natale Walter

AU - Maniscalco, Sabrina

AU - Lo Gullo, Nicolino

PY - 2019/1/1

Y1 - 2019/1/1

N2 - A numerical method to solve the set of Dyson-like equations in the framework of non-equilibrium Green's functions is presented. The technique is based on the self-consistent solution of the Dyson equations for the interacting single-particle Green's function once a choice for the self-energy, functional of the single-particle Green's function itself, is made. The authors briefly review the theory of the non-equilibrium Green's functions in order to highlight the main point useful in discussing the proposed technique. Then, the numerical implementationis presented and discussed, which is based on the distribution of the Keldysh components of the Green's function and the self-energy on a grid of processes. It is discussed how the structure of the considered self-energy approximations influences the distribution of the matrices in order to minimize the communication time among processes and which should be considered in the case of other approximations. The authors give an example of the application of this technique to the case of quenches in ultracold gases and to the single impurity Anderson model, also discussing the convergence and the stability features of the approach.

AB - A numerical method to solve the set of Dyson-like equations in the framework of non-equilibrium Green's functions is presented. The technique is based on the self-consistent solution of the Dyson equations for the interacting single-particle Green's function once a choice for the self-energy, functional of the single-particle Green's function itself, is made. The authors briefly review the theory of the non-equilibrium Green's functions in order to highlight the main point useful in discussing the proposed technique. Then, the numerical implementationis presented and discussed, which is based on the distribution of the Keldysh components of the Green's function and the self-energy on a grid of processes. It is discussed how the structure of the considered self-energy approximations influences the distribution of the matrices in order to minimize the communication time among processes and which should be considered in the case of other approximations. The authors give an example of the application of this technique to the case of quenches in ultracold gases and to the single impurity Anderson model, also discussing the convergence and the stability features of the approach.

KW - Dyson equation

KW - many-body perturbation theory

KW - non-equilibrium Green's functions

KW - numerical methods

UR - http://www.scopus.com/inward/record.url?scp=85062727951&partnerID=8YFLogxK

U2 - 10.1002/pssb.201800501

DO - 10.1002/pssb.201800501

M3 - Article

AN - SCOPUS:85062727951

JO - PHYSICA STATUS SOLIDI B: BASIC SOLID STATE PHYSICS

JF - PHYSICA STATUS SOLIDI B: BASIC SOLID STATE PHYSICS

SN - 0370-1972

M1 - 1800501

ER -