Excitations of an Inhomogeneous Electronic System: From Ambient Conditions to Warm Dense Matter

Warm dense matter (WDM) is the state of matter at high pressures and temperatures. WDM is
relevant both for practical applications and for fundamental science. The practical significance is
due to the generation of the WDM state in experiments on nuclear fusion and the creation of new
materials under extreme conditions. From the point of view of fundamental science, the relevance
of WDM is due to the extreme conditions in the interiors of planets and stars.
Many questions regarding the interplay of quantum degeneracy, thermal excitations, and strong
correlations effects in WDM remain open. To solve this problem, we use an externally perturbed
WDM to investigate how electronic structure and excitations are affected by thermal excitations
and density inhomogeneities. The results are reported in our recent articles [1-4], where we
presented: a study of the quality of various exchange-correlation functionals in the KS-DFT method
[1,2]; the change in electronic excitations due to strong inhomogeneity and thermal effects [3]; and
a new KS-DFT based methodology for the investigation of the non-linear response of electrons
across temperature regimes relevant for WDM [4].

[1] Z. Moldabekov, T. Dornheim, M. Boehme, J. Vorberger, A. Cangi, J. Chem.Phys. 155 (2021)
124116.
[2] Z. Moldabekov, T. Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105 (2022) 035134.
[3] Z. Moldabekov, T. Dornheim, A. Cangi, Sci. Rep. 12 (2022) 1093.
[4] Z. Moldabekov, J. Vorberger, T. Dornheim, J. Chem. Theory Comput. 18 (2022) 2900