Electron Photoemission Spectra of Molecular Structure and Quantum Fluctuation Theorem

Abstract

The possibility of applying the quantum fluctuation theorem (QFT) to deep-lying electron orbitals in atoms photon↔electron transitions cross-section spectra is considered. Such spectra can only be obtained as a function of the difference between measurable excitation energy and final state energy. It is shown that spectra in this function do not satisfy the QFT. An assumption is made about the change in cross-section spectra by screening the transition excitations by an ensemble of neighboring orbitals. A screening coefficient is constant across the observed spectrum and accounts for the reduction of excitation energy (cross-section) to the elementary started state due to the screening is introduced into the QFT relations for such transition cross-sections. With screening considered, the spectra satisfy QFT relations. These assumptions are applied to X-ray photoemission spectra of electrons, inverse X-ray photoemission spectra, and electron energy loss (absorption) spectra. It is found that screening weakens the non-valence atomic orbital’s transition cross-section by an order of magnitude or even more, but not for the outer valence ones, only by several times. It was found that the identification of purely electronic transition position using QFT relations from the observed spectrum depends on the screening coefficient.