4 research outputs found
Waveguide QED with Moessbauer Nuclei
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 a new 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 develop 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 spatio-temporal
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
microns, on the scale of practical photolithography. This allows for the design
of special sample geometries to explore the resonant response or micro-striped
waveguides, opening a new toolbox of geometrical design for hard X-ray quantum
optics.Comment: 29 pages, 19 figure
Driven electronic bridge processes via defect states in Th-doped crystals
The electronic defect states resulting from doping Th in CaF
offer a unique opportunity to excite the nuclear isomeric state Th at
approximately 8 eV via electronic bridge mechanisms. We consider bridge schemes
involving stimulated emission and absorption using an optical laser. The role
of different multipole contributions, both for the emitted or absorbed photon
and nuclear transition, to the total bridge rates are investigated
theoretically. We show that the electric dipole component is dominant for the
electronic bridge photon. In contradistinction, the electric quadrupole channel
of the Th isomeric transition plays the dominant role for the bridge
processes presented. The driven bridge rates are discussed in the context of
background signals in the crystal environment and of implementation methods. We
show that inverse electronic bridge processes quenching the isomeric state
population can improve the performance of a solid-state nuclear clock based on
Th
Scientific Opportunities with an X-ray Free-Electron Laser Oscillator
An X-ray free-electron laser oscillator (XFELO) is a new type of hard X-ray
source that would produce fully coherent pulses with meV bandwidth and stable
intensity. The XFELO complements existing sources based on self-amplified
spontaneous emission (SASE) from high-gain X-ray free-electron lasers (XFEL)
that produce ultra-short pulses with broad-band chaotic spectra. This report is
based on discussions of scientific opportunities enabled by an XFELO during a
workshop held at SLAC on June 29 - July 1, 2016Comment: 21 pages, 12 figure
Scientific Opportunities with an X-ray Free-Electron Laser Oscillator
An X-ray free-electron laser oscillator (XFELO) is a new type of hard X-ray source that would produce fully coherent pulses with meV bandwidth and stable intensity. The XFELO complements existing sources based on self-amplified spontaneous emission (SASE) from high-gain X-ray free-electron lasers (XFEL) that produce ultra-short pulses with broad-band chaotic spectra. This report is based on discussions of scientific opportunities enabled by an XFELO during a workshop held at SLAC on June 29 - July 1, 201