Modeling electron dynamics coupled to continuum states in finite volumes with absorbing boundaries

European Physical Journal B 88, (2015)

Modeling electron dynamics coupled to continuum states in finite volumes with absorbing boundaries

Umberto De Giovannini, Ask Hjorth Larsen, Angel Rubio

Absorbing boundaries are frequently employed in real-time propagation of the Schro ̈dinger equa- tion to remove spurious reflections and efficiently emulate outgoing boundary conditions. These conditions are a fundamental ingredient for the calculation of observables involving infinitely extended continuum states in finite volumes. In the literature, several boundary absorbers have been proposed. They mostly fall into three main families: mask function absorbers, complex absorbing potentials, and exterior complex- scaled potentials. To date none of the proposed absorbers is perfect, and all present a certain degree of reflections. Characterization of such reflections is thus a critical task with strong implications for time- dependent simulations of atoms and molecules. We introduce a method to evaluate the reflection properties of a given absorber and present a comparison of selected samples for each family of absorbers. Further, we discuss the connections between members of each family and show how the same reflection curves can be obtained with very different absorption schemes.

Additional Information

Download
Preprint - 2.3 MB
Doi
http://dx.doi.org/10.1140/epjb/e2015-50808-0
arxiv
http://arxiv.org/abs/1409.1689
Notes
The authors acknowledge financial support from the European Research Council Advanced Grant DYNamo (ERC-2010-AdG- 267374), the European Commission project CRONOS (Grant No. 280879-2 CRONOS CP-FP7), Spanish Grants (FIS2010-21282-C02-01 and PIB2010US-00652), and Grupos Consolidados UPV/EHU del Gobierno Vasco (IT-578-13). U.D.G. designed the study and wrote the first version of the paper, A.H.L. contributed to the writing and discussion, A.R. supervised and contributed to the discussion

Related Projects

Related Research Areas