Inverse design of artificial two-level systems with M\"ossbauer nuclei in thin-film cavities

TL;DR

This paper introduces an inverse design method for artificial two-level systems using M"ossbauer nuclei in thin-film cavities, enabling optimized x-ray quantum optical environments and advancing the development of tunable x-ray quantum devices.

Contribution

It develops a comprehensive optimization framework for designing artificial two-level systems with M"ossbauer nuclei, providing qualitative insights and generalizable methods for future x-ray cavity engineering.

Findings

Discovery of qualitative insights into x-ray photonic environments.

Development of an efficient inverse design and optimization method.

Potential to improve x-ray cavity performance and design of advanced quantum schemes.

Abstract

Thin-film cavities containing layers of M\"ossbauer nuclei have been demonstrated to be a rich platform for x-ray quantum optics. At low excitation, these systems can be described by effective few-level schemes, thereby providing tunable artificial quantum systems at hard x-ray energies. With the recent advent of an ab initio theory, a numerically efficient description of these systems is now possible. On this basis, we introduce the inverse design and develop a comprehensive optimization for an archetype system with a single resonant layer, corresponding to an artificial two-level scheme. We discover a number of qualitative insights into x-ray photonic environments for nuclei that will likely impact the design of future x-ray cavities and thereby improve their performance. The presented methods readily generalize beyond the two-level case and thus provide a clear perspective towards the inverse design of more advanced tunable x-ray quantum optical level schemes.