Towards nonlinear optics with M\"ossbauer nuclei using x-ray cavities

TL;DR

This paper develops a theoretical framework for achieving nonlinear optics with M"ossbauer nuclei in x-ray cavities, identifying optimal cavity geometries and conditions to enhance nuclear excitation using focused x-ray pulses.

Contribution

It provides the first comprehensive theory of nonlinear nuclear excitation in thin-film x-ray cavities and suggests cavity designs to improve excitation efficiency.

Findings

Identifies cavity geometries with broad resonances for enhanced excitation

Proposes methods to mitigate radiation damage during excitation

Establishes experimental conditions for nonlinear nuclear optics

Abstract

Strong excitation of nuclear resonances, particularly of M\"ossbauer nuclei, has been a longstanding goal and the advance of novel x-ray sources is promising new options in this regard. Here we map out the necessary experimental conditions for the more general goal of realizing nonlinear optics with nuclei and compare with available technology. In particular, we present a comprehensive theory of nonlinear nuclear excitation in thin-film x-ray cavities by focused x-ray pulses. We thereby identify cavity geometries with broad resonances which allow one to boost the nuclear excitation even at moderately tight focusing and offer the possibility to mitigate radiation damage.