Two-dimensional correlation analysis for x-ray photoelectron spectroscopy

Abstract X-ray photoelectron spectroscopy (XPS) measures the binding energy of core-level electrons, which are well-localised to specific atomic sites in a molecular system, providing valuable information on local chemical environment. The technique relies measuring spectrum upon x-ray photoionisation, and resolution is often limited by bandwidth ionising pulse. This particularly problematic for time-resolved XPS, where desired time enforces fundamental lower limit source. In this work, we report novel correlation analysis exploits between spectra improve XPS measurements. We show that with correlation-based spectral-domain ghost imaging method can achieve sub-bandwidth enables sources large or spectral jitter, previously considered unfeasible