Electron-induced nonlinear dynamics in atomic chains
New paper exploring nonlinear light-matter interactions induced by free electrons.
Low-energy free electrons can induce a nonlinear optical response in the collective oscillations of conduction electrons in nanostructured materials, but the dependence of this free-electron-induced nonlinearity on a material’s intrinsic electronic properties is not fully understood. In a new Letter published in Physical Review Research. POLIMA researchers Line Jelver and Joel Cox report time-domain simulations of electron-induced nonlinear dynamics in a paradigmatic model of condensed matter physics: linear atomic chains, which can be parametrized to exhibit metallic, semiconducting, or topologically insulating character. The simulations reveal the crucial role of electronic structure in determining the nature of the nonlinear response to free electrons, while establishing the Fermi velocity in the target system as the threshold speed at which an external free electron triggers nonlinear interactions. These findings can guide future experimental efforts to observe electron-induced nonlinear phenomena in nanostructured materials.
The work was supported by the Sapere Aude research leader program from the Independent Research Fund Denmark, VILLUM Fonden, and the Danish National Research Foundation.