Title
Efficient numerical method for evaluating normal and anomalous time-domain equilibrium Green's functions in inhomogeneous systems
Date Issued
15 September 2021
Access level
open access
Resource Type
journal article
Author(s)
Löthman T.
Triola C.
Black-Schaffer A.M.
Uppsala University
Publisher(s)
American Physical Society
Abstract
In this work we develop EPOCH (equilibrium propagator by orthogonal polynomial chain), a computationally efficient method to calculate the time-dependent equilibrium Green's functions, including the anomalous Green's functions of superconductors, to capture the time evolution in large inhomogeneous systems. The EPOCH method generalizes the Chebyshev wave-packet propagation method from quantum chemistry and efficiently incorporates the Fermi-Dirac statistics that is needed for equilibrium quantum condensed matter systems. The computational cost of EPOCH scales only linearly in the system degrees of freedom, generating an extremely efficient algorithm also for very large systems. We demonstrate the power of the EPOCH method by calculating the time evolution of an excitation near a superconductor-normal metal interface in two and three dimensions, capturing transmission as well as normal and Andreev reflections.
Volume
104
Issue
12
Language
English
OCDE Knowledge area
Astronomía Ciencias de la computación
Scopus EID
2-s2.0-85114477687
Source
Physical Review B
ISSN of the container
24699950
Sponsor(s)
We thank D. Chakraborty, P. Dutta, and Y. Tanaka for helpful discussions and P. San-José for important comments on the manuscript. We acknowledge financial support from the Swedish Research Council (Vetenskapsrådet Grant No. 2018-03488), the Knut and Alice Wallenberg Foundation through the Wallenberg Academy Fellows program, and the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (Grant No. ERC-2017-StG-757553), and the EU-COST Action CA-16218 Nanocohybri.
Sources of information: Directorio de Producción Científica Scopus