Many body shake up in X-ray photoemission from bundles of lithium-intercalated single-walled carbon nanotubes

We present a model to describe the asymmetric features of X-ray photoemission spectra from bundles of clean and Li-intercalated single-walled carbon nanotubes due to shake up processes in both metallic and semiconducting bands, with energy gaps below ∼1 eV. Using the tight binding method, we determine the effect of the suddenly created core hole – in the 1s-state of a carbon atom – on the many electron states of π and π∗ bands. We compute the energy distributions of many body excitations created at the expense of the photoelectron energy in (10, 10) and (16, 0) tubes, thus, obtaining an merit function for the X-ray photo-peak, resulting from the superposition of a symmetric and an asymmetric components. The latter describes to the average behavior of shake up electrons in tubes of different chirality and changes with the concentration of dopants.