106
R. Röhlsberger and J. Evers
strong coupling of light and matter where phenomena like normal mode splitting
and Rabi oscillations appear. These developments establish Mössbauer nuclei as a
promising platform to study quantum optical effects at x-ray energies. In turn, these
effects bear potential to advance the instrumentation and applications of Mössbauer
science as a whole.
3.1 Introduction
The study and applications of light-matter interactions in the optical regime have
undergone a revolutionary development over the last decades, to the point where
now quantum technologies become a reality. Quantum mechanical phenomena in
this interaction are the domain of quantum optics, which encompasses semiclassical
setups exploiting the quantum-mechanical nature of the matter, as well as cases in
which the quantum character of the light has to be taken into account [1–4]. A key
driver for the advancement continues to be the progress in laser source technology,
also beyond the visible light regime.
3.1.1 Light Sources for X-Ray Quantum Optics
X-ray quantum optics has not been very prominent in the early phase of x-ray science,
not least because of source limitations. For instance, unlike a laser source, typical
x-ray sources emit photons into a large number of electromagnetic-field modes, severly restricting the control possibilities offered by the light. This is no longer the case
for experimental conditions that can be realized with modern synchrotron radiation
sources and x-ray free-electron lasers, together with increasing source brilliance and
advances in x-ray optical elements and detection techniques (for a view on the evolution of the brilliance of x-ray sources, see Fig. 3.1). As a result, the study of quantum
optical effects in the interaction of light and matter moves within reach at hard x-ray
energies, and is becoming increasingly relevant for new enabling experimental possibilities and for the interpretation of data obtained at these radiation sources. Broadly
speaking, the long-term goals of this approach are to fully exploit the capabilities
offered by the new x-ray sources, and to continue the success story of quantum optics
at hard x-ray energies.
3.1.2 X-Ray Quantum Optics with Atomic Resonances
Two key concepts of quantum optics are coherence and interference. Sharp resonances are favorable in this regard, since the narrow linewidth translates into comparably long lifetimes of coherent superpositions of the involved atomic states. At
R. Röhlsberger and J. Evers
strong coupling of light and matter where phenomena like normal mode splitting
and Rabi oscillations appear. These developments establish Mössbauer nuclei as a
promising platform to study quantum optical effects at x-ray energies. In turn, these
effects bear potential to advance the instrumentation and applications of Mössbauer
science as a whole.
3.1 Introduction
The study and applications of light-matter interactions in the optical regime have
undergone a revolutionary development over the last decades, to the point where
now quantum technologies become a reality. Quantum mechanical phenomena in
this interaction are the domain of quantum optics, which encompasses semiclassical
setups exploiting the quantum-mechanical nature of the matter, as well as cases in
which the quantum character of the light has to be taken into account [1–4]. A key
driver for the advancement continues to be the progress in laser source technology,
also beyond the visible light regime.
3.1.1 Light Sources for X-Ray Quantum Optics
X-ray quantum optics has not been very prominent in the early phase of x-ray science,
not least because of source limitations. For instance, unlike a laser source, typical
x-ray sources emit photons into a large number of electromagnetic-field modes, severly restricting the control possibilities offered by the light. This is no longer the case
for experimental conditions that can be realized with modern synchrotron radiation
sources and x-ray free-electron lasers, together with increasing source brilliance and
advances in x-ray optical elements and detection techniques (for a view on the evolution of the brilliance of x-ray sources, see Fig. 3.1). As a result, the study of quantum
optical effects in the interaction of light and matter moves within reach at hard x-ray
energies, and is becoming increasingly relevant for new enabling experimental possibilities and for the interpretation of data obtained at these radiation sources. Broadly
speaking, the long-term goals of this approach are to fully exploit the capabilities
offered by the new x-ray sources, and to continue the success story of quantum optics
at hard x-ray energies.
3.1.2 X-Ray Quantum Optics with Atomic Resonances
Two key concepts of quantum optics are coherence and interference. Sharp resonances are favorable in this regard, since the narrow linewidth translates into comparably long lifetimes of coherent superpositions of the involved atomic states. At