High harmonic generation in Mott Insulators: Insights from dynamical mean field theory

Ultra-strong fields can drive highly nonlinear electron dynamics in the
solid, where Bloch electrons explore large portions of the Brillouin
zone within a single field cycle. In correlated electron systems, this
nonlinear dynamics in combination with strong interactions promises new
pathways to probe correlation effects, or even switch between different
phases in the solid. We use dynamical mean-field theory [1] to study the
electronic structure of quantum materials in the presence of strong
fields. In Mott insulators we find clear signals of high-harmonic
generation [2], in spite of the incoherent carrier motion, which allows
to infer information about the local interactions. Moreover, sub-cycle
resolved dynamics in multi-band systems can transiently reveal hidden
properties such as atomic multiplets [3] through field-induced
localization. Finally, we demonstrate that strong fields can also
directly be used to manipulate low-energy degrees of freedom such as
spin and orbital order in correlated materials, and possibly switch
between metastable states.

[1] Hideo Aoki, Naoto Tsuji, Martin Eckstein, Marcus Kollar, Takashi
Oka, and Philipp Werner, Rev. Mod. Phys. 86, 779 (2014)
[2] Yuta Murakami, Martin Eckstein, and Philipp Werner, Phys. Rev. Lett.
121, 057405 (2018)
[3] Nagamalleswararao Dasari, Jiajun Li, Philipp Werner, and Martin
Eckstein, Phys. Rev. B 101, 161107(R) (2020)