Abstracts Book - IMRC 2018

• SD1-O042 Invited Talk
ELECTRONIC STOPPING IN CONDENSED MATTERS:
UNDERSTANDING ELECTRONIC EXCITATION DYNAMICS UNDER
ION IRRADIATION
Yosuke Kanai 1
1 University of North Carolina at Chapel Hill, Department of Chemistry, United States.
Non-equilibrium response of excited electrons in condensed matter systems
under ion irradiation is described by so-called electronic stopping phenomenon.
The projectile ions bear a highly localized electric field that is quite
heterogeneous at the atomistic scale, and massive electronic excitations are
produced in the electronic stopping process. Understanding this phenomenon
in condensed matter systems under ion irradiation has implications in various
modern technologies, ranging nuclear fission/fusion reactors, to semiconductor
devices for aerospace missions, to cancer therapy based on proton beam
radiation. Electronic stopping has been long studied within linear response
theory framework (e.g. Bethe theory), but recent advances in high-performance
computers allow us to describe the phenomena beyond such treatment through
the use of our recently-developed large-scale real-time time-dependent density
functional theory. In this talk, I will discuss how non-equilibrium simulations
enable us to study this electronic excitation process, in particular for the
importance case of liquid water, semiconductors, and DNA under proton and
alpha-particle irradiation. Using the concept of maximally-localized Wannier
functions in the electronic stopping, it is possible to gain insight into the
spatially-heterogeneous excitation dynamics at the level of molecular details.
Keywords: first-principles calculation, condensed matter, time-dependent DFT
Presenting authors email: ykanai@unc.edu