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:1607.04116

Inducing and detecting collective population inversions of Mössbauer nuclei

Kilian P. Heeg, Christoph H. Keitel, Jörg Evers

Published Jul 14, 2016• 6 citations
arXivHTMLPDF

Abstract

Up to now, experiments involving Mössbauer nuclei driven by x-rays have been restricted to the low-excitation regime. Here, a setup is proposed which promises significant excitation, ideally exceeding full inversion of the nuclear ensemble, at x-ray light sources under construction. We further introduce a method to experimentally verify such inversions, in which population inversions manifest themselves in symmetry flips of suitably recorded spectra. It neither requires per-shot spectra of the incoming x-ray pulses, nor absolute measurements of the scattered light intensity.

DOI
10.48550/arxiv.1607.04116

Related papers

Characterization and detection method for x-ray excitation of Mössbauer nuclei beyond the low-excitation regime

Lukas Wolff, Jörg Evers

Up to now, experiments involving M\"ossbauer nuclei have been restricted to the low-excitation regime (LER). The reason for this is the narrow spectral linewidth of the nuclei. This defining feature enables M\"ossbauer spectroscopy with remarkable resolution and convenient control and measurements in the time domain, but at the same time implies that only a tiny part of the photons delivered by accelerator-based x-ray sources with orders-of-magnitude larger pulse bandwidth are resonant with the nuclei. X-ray free-electron lasers promise a substantial enhancement of the number of nuclear-resonant photons per pulse, such that excitations beyond the LER come within reach. This raises the question of how the onset of nonlinear excitations could be experimentally verified. Here, we develop and explore a method to detect an excitation of nuclear ensembles beyond the LER for ensembles of nuclei embedded in x-ray waveguides. It relies on the comparison of the x rays coherently and incoherently scattered off of the nuclei. As a key result, we show that the ratio of the two observables is constant within the LER, essentially independent of the details of the nuclear system and the characteristics of the exciting x rays. Conversely, deviations from this equivalence serve as a direct indication of excitations beyond the LER. Building upon this observation, we develop a variety of experimental signatures both, for near-instantaneous impulsive and for temporally extended nonimpulsive x-ray excitation. Correlating coherently and incoherently scattered intensities further allows one to compare theoretical models of nonlinear excitations more rigorously to corresponding experiments.

Physical Review A•Oct 16, 2023•3 citations

Mössbauer medium with a hidden nuclear population inversion and negative absorption of gamma quanta

Лев Абрамович Ривлин

We consider physical foundations of an eventual experiment aimed at observing stimulated gamma-photon emission of long-lived Mössbauer isomers through selective frequency modulation of gamma-resonances establishing hidden population inversion without exceeding the number of excited nuclei over unexcited ones and without additional pumping. The examples of suitable nuclei and numerical estimates of the parameters are presented.

Quantum Electronics•Jun 30, 2011•0 citations

Coherent Control of Nuclear Excited State Population Using X-ray Free Electron Lasers

André Junker

The direct interaction between nuclei and strong electromagnetic fields generated by novel coherent x-ray light sources such as the x-ray free electron laser is studied. We investigate the case of various stable or long-lived isotopes with energetically low-lying excited states, where the laser drives the nuclear transition from the ground to the first excited state. We therefore consider the nucleus as a two-level system including the corresponding hyperfine levels in our theoretical description. The performance of present and upcoming x-ray free electron laser facilities in coherently controlling the nuclear excited state population is analyzed for setups involving both solid state as well as accelerated nuclear targets to bridge the gap between photon and transition frequency. Current and predicted laser parameters are applied to calculate excited state populations and signal photon rates of nuclei after a radiation pulse, finding significant improvements compared to former calculations. Furthermore, we determine the parameters necessary to transfer substantial amounts of the nuclear ground state population to the excited state, and therefore to bring nuclear Rabi-oscillation within reach. Additionally, we take into account for the first time collective effects that take place in solid state targets and show that they may provide a significant effect in broadening natural linewidths of nuclear levels depending on the experimental setup. Our findings support the case of nuclear quantum optics for XFEL applications. Therefore, one hopes that eventually coherent control of nuclear transitions can be successfully applied in a number of areas in nuclear physics including preparation, control and detection methods.

•Jan 1, 2011•0 citations

Simulated emission from cooled nuclear beams

Лев Абрамович Ривлин

An analysis is made of an experimental setup to observe negative absorption of γ photons by nuclei without total population inversion. The system includes an intensive cooling operation which radically suppresses the negative influence of the Doppler broadening of a non-Mössbauer line. Estimates indicate that a positive gain is feasible.

Soviet Journal of Quantum Electronics•May 31, 1992•9 citations

Gamma-ray laser operating with the assistance of the recoil of free nuclei

Лев Абрамович Ривлин

The concept of a γ-ray laser which makes use of the kinematic shift and the splitting of the spectral lines of radiative γ-transitions observed in an ensemble of free nuclei owing to recoil is considered. These effects form a prerequisite for the formation of hidden population inversion with no excess of the number of excited emitters over the number of unexcited ones, for implementation of a broadband unperturbing x-ray pump in an unconventional 'two-level' scheme, for the manifestation of anisotropic quantum amplification without any reflecting structures, etc. These attractive properties offer strong possibilities of staging an initial demonstration nuclear γ-ray laser experiment.

Quantum Electronics•Jun 30, 1999•16 citations

Optical method for observing the hidden population inversion of nuclear states (possible experimental scheme)

Лев Абрамович Ривлин

The possibility of observation of the hidden nuclear inversion below the lasing threshold from a change in the optical spectra of atoms containing the nuclei is considered.

Quantum Electronics•Apr 30, 2002•1 citation
Up to now, experiments involving Mössbauer nuclei driven by x-rays have been restricted to the low-excitation regime. Here, a setup is proposed which promises significant excitation, ideally exceeding full inversion of the nuclear ensemble, at x-ray light sources under construction. We further introduce a method to experimentally verify such inversions, in which population inversions manifest themselves in symmetry flips of suitably recorded spectra. It neither requires per-shot spectra of the incoming x-ray pulses, nor absolute measurements of the scattered light intensity.
Up to now, experiments involving M\"ossbauer nuclei have been restricted to the low-excitation regime (LER). The reason for this is the narrow spectral linewidth of the nuclei. This defining feature enables M\"ossbauer spectroscopy with remarkable resolution and convenient control and measurements in the time domain, but at the same time implies that only a tiny part of the photons delivered by accelerator-based x-ray sources with orders-of-magnitude larger pulse bandwidth are resonant with the nuclei. X-ray free-electron lasers promise a substantial enhancement of the number of nuclear-resonant photons per pulse, such that excitations beyond the LER come within reach. This raises the question of how the onset of nonlinear excitations could be experimentally verified. Here, we develop and explore a method to detect an excitation of nuclear ensembles beyond the LER for ensembles of nuclei embedded in x-ray waveguides. It relies on the comparison of the x rays coherently and incoherently scattered off of the nuclei. As a key result, we show that the ratio of the two observables is constant within the LER, essentially independent of the details of the nuclear system and the characteristics of the exciting x rays. Conversely, deviations from this equivalence serve as a direct indication of excitations beyond the LER. Building upon this observation, we develop a variety of experimental signatures both, for near-instantaneous impulsive and for temporally extended nonimpulsive x-ray excitation. Correlating coherently and incoherently scattered intensities further allows one to compare theoretical models of nonlinear excitations more rigorously to corresponding experiments.
The direct interaction between nuclei and strong electromagnetic fields generated by novel coherent x-ray light sources such as the x-ray free electron laser is studied. We investigate the case of various stable or long-lived isotopes with energetically low-lying excited states, where the laser drives the nuclear transition from the ground to the first excited state. We therefore consider the nucleus as a two-level system including the corresponding hyperfine levels in our theoretical description. The performance of present and upcoming x-ray free electron laser facilities in coherently controlling the nuclear excited state population is analyzed for setups involving both solid state as well as accelerated nuclear targets to bridge the gap between photon and transition frequency. Current and predicted laser parameters are applied to calculate excited state populations and signal photon rates of nuclei after a radiation pulse, finding significant improvements compared to former calculations. Furthermore, we determine the parameters necessary to transfer substantial amounts of the nuclear ground state population to the excited state, and therefore to bring nuclear Rabi-oscillation within reach. Additionally, we take into account for the first time collective effects that take place in solid state targets and show that they may provide a significant effect in broadening natural linewidths of nuclear levels depending on the experimental setup. Our findings support the case of nuclear quantum optics for XFEL applications. Therefore, one hopes that eventually coherent control of nuclear transitions can be successfully applied in a number of areas in nuclear physics including preparation, control and detection methods.
The concept of a γ-ray laser which makes use of the kinematic shift and the splitting of the spectral lines of radiative γ-transitions observed in an ensemble of free nuclei owing to recoil is considered. These effects form a prerequisite for the formation of hidden population inversion with no excess of the number of excited emitters over the number of unexcited ones, for implementation of a broadband unperturbing x-ray pump in an unconventional 'two-level' scheme, for the manifestation of anisotropic quantum amplification without any reflecting structures, etc. These attractive properties offer strong possibilities of staging an initial demonstration nuclear γ-ray laser experiment.