Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2305.11647 · Physical Review A

Waveguide QED with Mössbauer nuclei

Petar Andrejić, Leon Merten Lohse, Adriana Pálffy

Published Jun 3, 2024• 6 citations
arXivHTMLPDF

Abstract

Thin-film nanostructures with embedded M\"ossbauer nuclei have been successfully used for x-ray quantum optical applications with hard x-rays coupling in grazing incidence. Here we address theoretically an alternative geometry, in which hard x rays are coupled in forward incidence (front coupling), setting the stage for waveguide QED with nuclear x-ray resonances. We present in a self-contained manner a general model based on the Green's function formalism of the field-nucleus interaction in one-dimensional waveguides and show that it combines aspects of both nuclear forward scattering, visible as dynamical beating in the spatiotemporal response, and the resonance structure from grazing incidence, visible in the spectrum of guided modes. The interference of multiple modes is shown to play an important role, resulting in beats with wavelengths on the order of tens of micrometers, on the scale of practical photolithography. This allows for the design of special sample geometries to explore the resonant response or microstriped waveguides, opening a toolbox of geometrical design for hard x-ray quantum optics.

DOI
10.1103/physreva.109.063702

Related papers

Collective Nuclear Excitation and Pulse Propagation in Single-Mode X-Ray Waveguides

Leon Merten Lohse, Petar Andrejić, Sven Velten +8 more

Waveguides offer a means to controllably couple atomic ensembles to the electromagnetic field therein. Here, we demonstrate x-ray propagation in planar thin-film waveguides coupled to Mössbauer nuclei under collective resonant excitation by short pulses of synchrotron radiation. We record x-ray photons that have been emitted into resonant modes of the waveguide. Depending on the geometry and mode of excitation, two fundamentally different signatures of the collective emission are observed, for which we present a unifying theoretical model. Our results form a new platform for waveguide quantum electrodynamics in the hard x-ray regime with the potential to provide a coherent narrow band source of x-rays on the nanometer scale.

arXiv:2403.06508•Physical Review Letters•Jun 27, 2025•2 citations

Green's-function formalism for resonant interaction of x rays with nuclei in structured media

Xiangjin Kong, Darrick E. Chang, Adriana Pálffy

The resonant interaction between x-ray photons and nuclei is one of the most exciting subjects in the burgeoning field of x-ray quantum optics. A resourceful platform used to date is thin-film x-ray cavities with embedded layers or M\"ossbauer nuclei such as $^{57}\mathrm{Fe}$. A quantum optical model based on the classical electromagnetic Green's function is developed to investigate theoretically the nuclear response inside the x-ray cavity. The model is versatile and provides an intuitive picture about the influence of the cavity structure on the resulting spectra. We test its predictive powers with the help of the semiclassical coherent scattering formalism simulations and discuss our results on increasing complexity of layer structures.

arXiv:2010.00249•Physical Review A•Sep 10, 2020•17 citations

X-ray quantum optics with Mössbauer nuclei embedded in thin-film cavities

Kilian P. Heeg, Jörg Evers

A promising platform for the emerging field of x-ray quantum optics consists of M\"ossbauer nuclei embedded in thin-film cavities probed by near-resonant x-ray light, as used in a number of recent experiments. Here we develop a quantum optical framework for the description of experimentally relevant settings involving nuclei embedded in x-ray waveguides. We apply our formalism to two settings of current experimental interest based on the archetype M\"ossbauer isotope ${}^{57}$Fe. For the present experimental conditions, we derive compact analytical expressions and show that the alignment of medium magnetization, as well as incident and detection polarization, enable the engineering of advanced quantum optical level schemes. The model encompasses nonlinear and quantum effects which could become accessible in future experiments.

arXiv:1305.4239•Physical Review A•Oct 15, 2013•58 citations

Hard X-ray quantum optics in thin-film nanostructures

Johann Haber

This thesis describes quantum optical experiments with x-rays with the aim of reaching the strong-coupling regime of light and matter. We make use of the interaction which arisesbetween resonant matter and x-rays in specially designed thin-film nanostructures which form x-ray cavities. Here, the resonant matter are Tantalum atoms and the Iron isotope $^{57}$Fe. Both limit the number of modes available to the resonant atoms for interaction, and enhances the interaction strength. Thus we have managed to observe a number of phenomena well-known in quantum optics, which are the building blocks for sophisticated applications in e.g. metrology. Among these are the strong coupling of light and matter and the concurrent exchange of virtual photons, often called Rabi oscillations. Furthermore we have designed and tested a type of cavity hitherto unused in x-ray optics. Finally, we develop a new method for synchrotron Mössbauer spectroscopy, which not only promises to yield high-resolution spectra, but also enables the retrieval of the phase of the scattered light. The results open new avenues for quantum optical experiments with x-rays, particularly with regards to the ongoing development of high-brilliance x-ray free-electron lasers.

•May 12, 2017•1 citation

Collective effects between multiple nuclear ensembles in an x-ray cavity-QED setup

Kilian P. Heeg, Jörg Evers

The setting of M\"ossbauer nuclei embedded in thin-film cavities has facilitated an aspiring platform for x-ray quantum optics as shown in several recent experiments. Here, we generalize the theoretical model of this platform that we developed earlier [Phys. Rev. A 88, 043828 (2013)]. The theory description is extended to cover multiple nuclear ensembles and multiple modes in the cavity. While the extensions separately do not lead to qualitatively new features, their combination gives rise to cooperative effects between the different nuclear ensembles and distinct spectral signatures in the observables. A related experiment by R\"ohlsberger et al. [Nature (London) 482, 199 (2012)] is successfully modeled, the scalings derived with semiclassical methods are reproduced, and a microscopic understanding of the setting is obtained with our quantum mechanical description.

arXiv:1504.02709•Physical Review A•Jun 3, 2015•29 citations

Collective Enhancement of Nuclear Excitation for a Nuclear Quantum Battery

Pravin Kumar Dahal, Kieran Hymas, Jack Muir +1 more

Current implementations of quantum batteries are constrained by limited energy density and short retention times associated with the electronic or molecular excitations. Here we propose a nuclear quantum battery based on collective excitation of the $^{57}$Fe nuclei of density $n$ embedded in a planar hard X-ray waveguide. Using a Green function waveguide-QED description, we study charging via excitation beyond linear response, where saturation and drive back-action reshape the incident pulse. We introduce a self-consistent waveform-engineering protocol that inhibits local radiative decay in the waveguide thus promoting absorption into high-lying collective nuclear excitation manifolds. We show an enhanced excitation cross section of the nuclear ensemble which yields superlinear charging, with maximum studied energy density scaling approximately like $n \sqrt{n}$. Our results provide a route to high-energy-density quantum charging at hard X-ray energies using contemporary X-ray sources and waveguide architectures by identifying nonlinear, collectively enhanced absorption as a key mechanism for nuclear quantum battery operation.

quant-pharXiv:2607.15319•Jul 17, 2026•0 citations
Thin-film nanostructures with embedded M"ossbauer nuclei have been successfully used for x-ray quantum optical applications with hard x-rays coupling in grazing incidence. Here we address theoretically an alternative geometry, in which hard x rays are coupled in forward incidence (front coupling), setting the stage for waveguide QED with nuclear x-ray resonances. We present in a self-contained manner a general model based on the Green's function formalism of the field-nucleus interaction in one-dimensional waveguides and show that it combines aspects of both nuclear forward scattering, visible as dynamical beating in the spatiotemporal response, and the resonance structure from grazing incidence, visible in the spectrum of guided modes. The interference of multiple modes is shown to play an important role, resulting in beats with wavelengths on the order of tens of micrometers, on the scale of practical photolithography. This allows for the design of special sample geometries to explore the resonant response or microstriped waveguides, opening a toolbox of geometrical design for hard x-ray quantum optics.
Waveguides offer a means to controllably couple atomic ensembles to the electromagnetic field therein. Here, we demonstrate x-ray propagation in planar thin-film waveguides coupled to Mössbauer nuclei under collective resonant excitation by short pulses of synchrotron radiation. We record x-ray photons that have been emitted into resonant modes of the waveguide. Depending on the geometry and mode of excitation, two fundamentally different signatures of the collective emission are observed, for which we present a unifying theoretical model. Our results form a new platform for waveguide quantum electrodynamics in the hard x-ray regime with the potential to provide a coherent narrow band source of x-rays on the nanometer scale.
The resonant interaction between x-ray photons and nuclei is one of the most exciting subjects in the burgeoning field of x-ray quantum optics. A resourceful platform used to date is thin-film x-ray cavities with embedded layers or M\"ossbauer nuclei such as 57Fe^{57}\mathrm{Fe}57Fe. A quantum optical model based on the classical electromagnetic Green's function is developed to investigate theoretically the nuclear response inside the x-ray cavity. The model is versatile and provides an intuitive picture about the influence of the cavity structure on the resulting spectra. We test its predictive powers with the help of the semiclassical coherent scattering formalism simulations and discuss our results on increasing complexity of layer structures.
A promising platform for the emerging field of x-ray quantum optics consists of M\"ossbauer nuclei embedded in thin-film cavities probed by near-resonant x-ray light, as used in a number of recent experiments. Here we develop a quantum optical framework for the description of experimentally relevant settings involving nuclei embedded in x-ray waveguides. We apply our formalism to two settings of current experimental interest based on the archetype M\"ossbauer isotope 57{}^{57}57Fe. For the present experimental conditions, we derive compact analytical expressions and show that the alignment of medium magnetization, as well as incident and detection polarization, enable the engineering of advanced quantum optical level schemes. The model encompasses nonlinear and quantum effects which could become accessible in future experiments.
This thesis describes quantum optical experiments with x-rays with the aim of reaching the strong-coupling regime of light and matter. We make use of the interaction which arisesbetween resonant matter and x-rays in specially designed thin-film nanostructures which form x-ray cavities. Here, the resonant matter are Tantalum atoms and the Iron isotope 57^{57}57Fe. Both limit the number of modes available to the resonant atoms for interaction, and enhances the interaction strength. Thus we have managed to observe a number of phenomena well-known in quantum optics, which are the building blocks for sophisticated applications in e.g. metrology. Among these are the strong coupling of light and matter and the concurrent exchange of virtual photons, often called Rabi oscillations. Furthermore we have designed and tested a type of cavity hitherto unused in x-ray optics. Finally, we develop a new method for synchrotron Mössbauer spectroscopy, which not only promises to yield high-resolution spectra, but also enables the retrieval of the phase of the scattered light. The results open new avenues for quantum optical experiments with x-rays, particularly with regards to the ongoing development of high-brilliance x-ray free-electron lasers.
The setting of M\"ossbauer nuclei embedded in thin-film cavities has facilitated an aspiring platform for x-ray quantum optics as shown in several recent experiments. Here, we generalize the theoretical model of this platform that we developed earlier [Phys. Rev. A 88, 043828 (2013)]. The theory description is extended to cover multiple nuclear ensembles and multiple modes in the cavity. While the extensions separately do not lead to qualitatively new features, their combination gives rise to cooperative effects between the different nuclear ensembles and distinct spectral signatures in the observables. A related experiment by R\"ohlsberger et al. [Nature (London) 482, 199 (2012)] is successfully modeled, the scalings derived with semiclassical methods are reproduced, and a microscopic understanding of the setting is obtained with our quantum mechanical description.
Current implementations of quantum batteries are constrained by limited energy density and short retention times associated with the electronic or molecular excitations. Here we propose a nuclear quantum battery based on collective excitation of the 57^{57}57Fe nuclei of density nnn embedded in a planar hard X-ray waveguide. Using a Green function waveguide-QED description, we study charging via excitation beyond linear response, where saturation and drive back-action reshape the incident pulse. We introduce a self-consistent waveform-engineering protocol that inhibits local radiative decay in the waveguide thus promoting absorption into high-lying collective nuclear excitation manifolds. We show an enhanced excitation cross section of the nuclear ensemble which yields superlinear charging, with maximum studied energy density scaling approximately like nnn \sqrt{n}nn​. Our results provide a route to high-energy-density quantum charging at hard X-ray energies using contemporary X-ray sources and waveguide architectures by identifying nonlinear, collectively enhanced absorption as a key mechanism for nuclear quantum battery operation.