Estimating the Fisher information from ARPES in general two-band models

Abstract

The Quantum Fisher information is frequently studied in the fields of quantum sensing and quantum metrology, as it specifies the sensitivity of a sensor through the Crámer-Rao bound, and in condensed matter physics where it relates to the quantum metric. Measuring the quantum Fisher information is therefore of significant current interest. In this work, we propose a scheme for measuring the quantum Fisher information with respect to any parameter in a general two-band solid state system using angle-resolved photoemission spectroscopy with carefully tuned incidence angles and light polarization. We investigate conditions under which this can be related back to information about the ground state of the material itself changing with system parameters.