Confinement induced enhancement of photoionization cross-section of an alkali-metal cluster inside a giant fullerene*

Giant fullerenes encasing atoms, clusters and nanocrystals have recently been developed [1] allowing researchers to investigate aspects of the dynamical response of an atom/cluster inside a fullerene cage to external stimuli. These endohedral systems hold the prospects of exciting applications. Thus, investigation of the influence of confining cage on the spectroscopy of atoms/cluster inside is a matter of significant interest [2]. In the present work, we investigate photoionization of Na_x inside a gigantic fullerene C_n. The ground state of the endohedral systems, Na_x@C_n (x=20, 40 and n=240, 540 respectively), is studied using a jellium-based density functional theory (DFT) approach with a gradient corrected exchange-correlation functional (LB94). Their photoionization (PI) dynamics is probed within an independent particle (IP) framework called linear-response DFT [3]. The results and comparisons with those of their isolated Na_x counterparts [4] show a significant enhancement in cross-sections owing to the confinement, even at the IP level.

References

[1] Ugarte D., Chem. Phys. Lett. 209, 99 (1993).

[2] Shangfeng Yang, Tao Wei and Fei Ji., Chem. Soc. Rev. 46, 500 (2017).

[3] J. Choi et al., Phys. Rev. A 95, 023404 (2017).

[4] Shaik et al., J. Phys. B 54, 125101 (2021).