The X-ray edge singularity in Quantum Dots

TL;DR

This paper analyzes the X-ray edge singularity in noninteracting quantum dots, providing analytical calculations of the absorption spectrum's singularity exponent across all parameter regimes and exploring its connections to work distributions and the Loschmidt echo.

Contribution

It extends analytical results for the X-ray edge singularity to all local level detunings in quantum dots and links these findings to work distributions and Loschmidt echo.

Findings

Calculated the singularity exponent analytically across parameter regimes

Extended known results to full range of local level detunings

Connected the singularity to work distributions and Loschmidt echo

Abstract

In this work we investigate the X-ray edge singularity problem realized in noninteracting quantum dots. We analytically calculate the exponent of the singularity in the absorption spectrum near the threshold and extend known analytical results to the whole parameter regime of local level detunings. Additionally, we highlight the connections to work distributions and to the Loschmidt echo.