Accurate and efficient simulation of photoemission spectroscopy via Kohn-Sham scattering states

TL;DR

This paper presents a new first-principles computational framework for simulating angle-resolved photoemission spectroscopy (ARPES) that is compatible with standard electronic-structure codes and provides detailed wave functions for analysis.

Contribution

It introduces a formalism based on the Kohn-Sham equation with scattering boundary conditions, enabling accurate, efficient ARPES simulations within existing density functional theory workflows.

Findings

Achieves excellent agreement with experimental ARPES data for graphene and WSe2.

Allows transparent analysis of matrix-element effects and experimental geometry.

Demonstrates robustness across a wide photon-energy range.

Abstract

We introduce an efficient first-principles framework for simulating angle-resolved photoemission spectroscopy (ARPES) based on the direct computation of photoelectron states as solutions of the Kohn-Sham equation with scattering boundary conditions. While the one-step theory of photoemission has a long and successful history, existing implementations are often tied to specialized electronic-structure formalisms. Our approach is formally equivalent to the Lippmann-Schwinger formulation, and it is directly compatible with standard plane-wave and real-space density functional theory codes, enabling seamless integration with advanced exchange-correlation functionals and modern electronic-structure workflows. By providing explicit photoelectron wave functions, the method allows for a transparent analysis of matrix-element effects, multiple scattering, and experimental geometry. We demonstrate the accuracy and predictive power of the framework through circular-dichroism ARPES simulations for monolayer graphene and bulk $2H$-WSe$_2$, achieving excellent agreement with experimental data over a wide photon-energy range. Our results establish a robust and accessible route toward quantitative ARPES modeling, opening the door to systematic studies of orbital textures, many-body effects, and nonequilibrium phenomena within widely used ab initio platforms.