A5022664502- Dark Matter and Cosmic Phenomena
- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Nonlinear Photonic Systems
- Particle physics theoretical and experimental studies
- Solid State Laser Technologies
- Nonlinear Waves and Solitons
- Cosmology and Gravitation Theories
Heinrich Heine University Düsseldorf
2018-2025
A possible implication of an ultralight dark matter field interacting with the standard model degrees freedom is oscillations fundamental constants. Here, we establish direct experimental bounds on coupling oscillating to up, down, and strange quarks gluons, for oscillation frequencies between 10 10^{8} Hz. We employ spectroscopic experiments that take advantage dependence molecular transition nuclear masses. Our results apply previously unexplored frequency bands improve existing at >5 MHz....
Ultralight dark matter (UDM) may manifest itself through oscillating fundamental constants of normal matter. These can be experimentally searched for by implementing two dissimilar oscillators producing a beat between their frequencies and analyzing the beat-frequency time series presence any temporal oscillations. Typically, such detector contains contributions from nonstationary noise. In order to reduce influence noise we propose demonstrate paired detectors: nominally identical detectors...
Properties of persistent spectral holes (SHs) relevant for frequency metrology have been investigated in the system $Eu^{3+}:Y_{2}SiO_{5}$ (0.5%) at crystallographic site 1 and a temperature $1.2$ Kelvin. Hole linewidths as small $0.6~kHz$ reliably achieved. The theoretically predicted $T^4$-dependence shift with has confirmed high precision. thermal hysteresis SH between $1.15~K$ $4.1~K$ was measured to be less than $6\cdot10^{-3}$ fractionally. After initially burning large ensemble SHs,...
We describe a spectroscopic method applicable to inhomogeneously broadened transitions. As test system we use suitable rare-earth-doped solids in which persistent spectral holes can be burned on weakly allowed electronic These systems are of interest as frequency references for the stabilization laser frequencies. In all experiments so far, and read out individually. Here present demonstration simultaneous burning readout sets holes, containing up 1024 individual by comb The such set leads...