Heide C, Boolakee T, Higuchi T, Hommelhoff P (2020)
Publication Type: Journal article
Publication year: 2020
URI: https://iopscience.iop.org/article/10.1088/2515-7647/ab7d82
DOI: 10.1088/2515-7647
Two-dimensional materials with hexagonal symmetry such as graphene and transition metal dichalcogenides are unique materials to study light-field-controlled electron dynamics inside of a solid. Around the $K$-point, the dispersion relation represents an ideal system to study intricately coupled intraband motion and interband (Landau-Zener) transitions driven by the optical field of phase-controlled few-cycle laser pulses. Based on the coupled nature of the intraband and interband processes, we have recently observed in graphene repeated coherent Landau-Zener transitions between valence and conduction band separated by around half an optical period of $\sim$1.3\,fs [Higuchi \textit{et al}., Nature 550, 224 (2017)]. Due to the low temporal symmetry of the applied laser pulse, a residual current density and a net electron polarization are formed. Here we show extended numerical data on the temporal evolution of the conduction band population of 2D materials with hexagonal symmetry during the light-matter interaction, yielding deep insights to attosecond-fast electron dynamics. In addition, we show that a residual ballistic current density is formed, which strongly increases when a band gap is introduced. Both, the sub-cycle electron dynamics and the resulting residual current are relevant for the fundamental understanding and future applications of strongly driven electrons in two-dimensional materials, including graphene or transition metal dichalcogenide monolayers.
APA:
Heide, C., Boolakee, T., Higuchi, T., & Hommelhoff, P. (2020). Sub-cycle temporal evolution of light-induced electron dynamics in hexagonal 2D materials. JPhys Photonics. https://doi.org/10.1088/2515-7647
MLA:
Heide, Christian, et al. "Sub-cycle temporal evolution of light-induced electron dynamics in hexagonal 2D materials." JPhys Photonics (2020).
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