Stopping power beyond the adiabatic approximation
Abstract
Energetic ions traveling in solids deposit energy in a variety of ways, being nuclear and electronic stopping the two avenues in which dissipation is usually treated. This separation between electrons and ions relies on the adiabatic approximation in which ions interact via forces derived from the instantaneous electronic ground state. In a more detailed view, in which nonadiabatic effects are explicitly considered, electronic excitations alter the atomic bonding, which translates into changes in the interatomic forces. In this work, we use time dependent density functional theory and forces derived from the equations of Ehrenfest dynamics that depend instantaneously on the timedependent electronic density. With them we analyze how the interionic forces are affected by electronic excitations in a model of a Ni projectile interacting with a Ni target, a metallic system with strong electronic stopping and shallow core level states. We find that the electronic excitations induce substantial modifications to the interionic forces, which translate into nuclear stopping power well above the adiabatic prediction. Particularly, we observe that most of the alteration of the adiabatic potential in early times comes from the ionization of the core levels of the target ions, not readily screened by the valence electrons.
 Authors:
 Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
 Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
 CIC Nanogune and DIPC, San Sebastian (Spain); Basque Foundation for Science Ikerbasque, Bilbao (Spain); Univ. of Cambridge, Cambridge (United Kingdom)
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Publication Date:
 Research Org.:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Sponsoring Org.:
 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22); EDDE; EFRC
 OSTI Identifier:
 1376569
 Report Number(s):
 LAUR1622678
Journal ID: ISSN 20452322; 100746
 Grant/Contract Number:
 AC0500OR22725; AC5206NA25396
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Scientific Reports
 Additional Journal Information:
 Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 20452322
 Publisher:
 Nature Publishing Group
 Country of Publication:
 United States
 Language:
 English
 Subject:
 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Condensedmatter physics; Electronic structure; timedependent density functional theory; electronic stopping power; ionization; nickel
Citation Formats
Caro, M., Correa, A. A., Artacho, E., and Caro, A.. Stopping power beyond the adiabatic approximation. United States: N. p., 2017.
Web. doi:10.1038/s41598017027803.
Caro, M., Correa, A. A., Artacho, E., & Caro, A.. Stopping power beyond the adiabatic approximation. United States. doi:10.1038/s41598017027803.
Caro, M., Correa, A. A., Artacho, E., and Caro, A.. 2017.
"Stopping power beyond the adiabatic approximation". United States.
doi:10.1038/s41598017027803. https://www.osti.gov/servlets/purl/1376569.
@article{osti_1376569,
title = {Stopping power beyond the adiabatic approximation},
author = {Caro, M. and Correa, A. A. and Artacho, E. and Caro, A.},
abstractNote = {Energetic ions traveling in solids deposit energy in a variety of ways, being nuclear and electronic stopping the two avenues in which dissipation is usually treated. This separation between electrons and ions relies on the adiabatic approximation in which ions interact via forces derived from the instantaneous electronic ground state. In a more detailed view, in which nonadiabatic effects are explicitly considered, electronic excitations alter the atomic bonding, which translates into changes in the interatomic forces. In this work, we use time dependent density functional theory and forces derived from the equations of Ehrenfest dynamics that depend instantaneously on the timedependent electronic density. With them we analyze how the interionic forces are affected by electronic excitations in a model of a Ni projectile interacting with a Ni target, a metallic system with strong electronic stopping and shallow core level states. We find that the electronic excitations induce substantial modifications to the interionic forces, which translate into nuclear stopping power well above the adiabatic prediction. Particularly, we observe that most of the alteration of the adiabatic potential in early times comes from the ionization of the core levels of the target ions, not readily screened by the valence electrons.},
doi = {10.1038/s41598017027803},
journal = {Scientific Reports},
number = 1,
volume = 7,
place = {United States},
year = 2017,
month = 6
}

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