Tools for investigating electronic excitation: experiment and multi-scale modelling

Modeling Time‐Resolved Kinetics in Solids Induced by Extreme Electronic Excitation

“…The transport MC module in TREKIS-4 uses an analog (eventby-event) algorithm for the propagation of classical trajectories of individual particles. [18] A particle's free-flight time between sequential scattering events is defined by its velocity and the freeflight path, 𝜆, which is approximated as a straight line and is sampled according to the exponential distribution…”

“…Upon relaxation of the electronic system, the target atoms react to the energy transferred at pico‐ to nanosecond timescales. [ 17,18 ] Finally, after cooling of the atomic system, the target may be left in a structurally modified state, observable experimentally. [ 1,9 ]…”

“…The quest for ever‐increasing precision inevitably leads to the quest for a deeper understanding of the fundamental processes of damage formation caused by the electronic excitation, and the development of appropriate models. [ 18 ]…”

“…Such models combine a few different approaches into one code tracing various aspects of the problem. [ 18 ] Each model covers its own characteristic scales, for example, ultrashort time scales may be described with precise ab initio approaches, whereas macroscopic timescales may be traced with more approximate continuous (thermodynamic) models. [ 18 ] In a more general case, in a hybrid approach, each model describes its own processes under appropriate conditions.…”

“…[ 18 ] Each model covers its own characteristic scales, for example, ultrashort time scales may be described with precise ab initio approaches, whereas macroscopic timescales may be traced with more approximate continuous (thermodynamic) models. [ 18 ] In a more general case, in a hybrid approach, each model describes its own processes under appropriate conditions. For example, different subsystems (electrons and ions) may be described with different methods.…”