A5036211019- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum, superfluid, helium dynamics
- Quantum optics and atomic interactions
- Advanced Frequency and Time Standards
- Advanced MRI Techniques and Applications
- Advanced NMR Techniques and Applications
- Dark Matter and Cosmic Phenomena
- Characterization and Applications of Magnetic Nanoparticles
- Advanced Chemical Physics Studies
- Mechanical and Optical Resonators
- Geomagnetism and Paleomagnetism Studies
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Magnetic Field Sensors Techniques
- Quantum Information and Cryptography
- High-pressure geophysics and materials
- Advanced Fiber Laser Technologies
- Spectroscopy and Quantum Chemical Studies
- Radiation Detection and Scintillator Technologies
- Physics of Superconductivity and Magnetism
- Quantum Mechanics and Applications
- Nuclear physics research studies
- Photonic and Optical Devices
Hals- Nasen- und Ohrenklinik Gießen
2024
University of Fribourg
2014-2023
University of Sussex
2020
Max Planck Institute of Quantum Optics
1992-2008
Physikalisch-Technische Bundesanstalt
2003-2004
University of Freiburg
2003
University of Bonn
1998-2002
Max Planck Society
1993-1997
Tübitak National Metrology Institute
1997
Université Paris Cité
1994
The authors review the history, current status, physical mechanisms, experimental methods, and applications of nonlinear magneto-optical effects in atomic vapors. They begin by describing pioneering work Macaluso Corbino over a century ago on linear (in which properties medium do not depend light power) vicinity resonances. These are then contrasted with various phenomena that have been studied both theoretically experimentally since late 1960s. In recent years, field magneto-optics has...
We present the result of an experiment to measure electric dipole moment (EDM) neutron at Paul Scherrer Institute using Ramsey's method separated oscillating magnetic fields with ultracold neutrons (UCN). Our measurement stands in long history EDM experiments probing physics violating time reversal invariance. The salient features this were use a Hg-199 co-magnetometer and array optically pumped cesium vapor magnetometers cancel correct for field changes. statistical analysis was performed...
We report on a search for ultralow-mass axionlike dark matter by analyzing the ratio of spin-precession frequencies stored ultracold neutrons and 199Hg atoms an axion-induced oscillating electric dipole moment neutron axion-wind effect. No signal consistent with is observed axion mass range 10−24≤ma≤10−17 eV. Our null result sets first laboratory constraints coupling to gluons, which improve astrophysical limits up 3 orders magnitude, also improves previous nucleons factor 40.Received 29...
Abstract Ultralight bosons such as axion-like particles are viable candidates for dark matter. They can form stable, macroscopic field configurations in the of topological defects that could concentrate matter density into many distinct, compact spatial regions small compared with Galaxy but much larger than Earth. Here we report results search transient signals from domain walls by using global network optical magnetometers exotic (GNOME) physics searches. We data, consisting correlated...
We present a multichannel cardiac magnetic field imaging system built in Fribourg from optical double-resonance Cs vapor magnetometers. It consists of 25 individual sensors designed to record maps the beating human heart by simultaneous measurements on grid 19 points over chest. The is operated as an array second order gradiometers using sophisticated digitally controlled feedback loops.
We present a theoretical study of the spectra produced by optical--radio-frequency double resonance devices, in which resonant linearly polarized light is used optical pumping and detection processes. extend previous work presenting algebraic results are valid for atomic states with arbitrary angular momenta, rf intensities, geometries. The only restriction made assumption low intensity. discussed view their use magnetometers.
The wave-particle duality of light plays a fundamental role in introductory courses on quantum mechanics. Traditionally the wave and particle aspects are demonstrated separate experiments which makes it difficult for students to understand their complementary nature. We present an experiment using single apparatus that demonstrates aspect, most importantly, coexistence. is based Mach-Zehnder interferometer beam attenuated so at each instant there only photon interferometer. In this way...
In case a mirror world with copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, n', could potentially mix undergo nn' oscillations. The interaction an magnetic field lift degeneracy between partners, diminish n' amplitude in wave function and, thus, suppress observability. We report experimental comparison ultracold storage trap without superimposed field. No influence is found assuming negligible fields, limit on oscillation time taunn' > 103 s (95%...
We have studied the ground-state Hanle effect (GSHE) excited by linearly polarized laser light on $D$${}_{1}$ line of cesium atoms. solved algebraically Liouville equation using irreducible tensor formalism, and derive an analytical expression for resonance shapes in a magnetic field arbitrary direction. The model predictions are excellent agreement with experimental observations various geometries. Our is valid $F\ensuremath{\rightarrow}{F}^{\ensuremath{'}}$ transitions low-power limit....
Light (pseudo-)scalar fields are promising candidates to be the dark matter in Universe. Under certain initial conditions early Universe and/or with types of self-interactions, they can form compact dark-matter objects such as axion stars or $Q$-balls. Direct encounters searched for by using a global network atomic magnetometers. It is shown that range masses and radii not ruled out existing observations, terrestrial encounter rate $Q$-balls sufficiently high (at least once per year)...
It has been proposed that there could be a mirror copy of the standard model particles, restoring parity symmetry in weak interaction on global level. Oscillations between neutral particle, such as neutron, and its counterpart potentially answer various standing issues physics today. Astrophysical studies terrestrial experiments led by ultracold neutron storage measurements have investigated to mirror-neutron oscillations imposed constraints theoretical parameters. Recently, further analysis...
The magnetic field produced by the human heart carries valuable information for medical research, as well diagnostics and screening disease. We have developed an optical method that allows us to produce movies of temporal dynamics cardiomagnetic map. While such been generated before with help SQUIDmagnetometers, our technique operates at room temperature promises substantial economic advantages.
We report a study of implantation and optical spectroscopy foreign atoms in solid-helium matrix. With sample more than ${10}^{9}$ Ba 1 ${\mathrm{cm}}^{3}$, storage time excess 5 hours has been demonstrated. Laser-induced fluorescence studies favor the assumption that isotropy trapping site for implanted is preserved during liquid-to-solid phase transition.
We extend our previous discussion of the resonant nonlinear Faraday effect in terms precession an induced quadrupole moment to realistic experimental situations where depopulation, repopulation, and hyperfine optical pumping contribute. derive, lowest order light intensity, analytical expression for magnetorotation angle near electric-dipole resonance atomic medium arbitrary spins. find excellent quantitative agreement with absolute measurements performed on Cs ${\mathit{D}}_{2}$ line.
We report the first observation of a spectral resonance in lateral displacement (Goos-H\"anchen shift) laser beam totally reflected from glass-cesium vapor interface. The line shape and magnitude effect are well described by model taking atom-wall collisions into account.
We performed ultracold neutron storage measurements to search for additional losses due (n) mirror-neutron (n′) oscillations as a function of an applied magnetic field B. In the presence mirror B′, would be maximal B≈B′. did not observe any indication nn′ and placed lower limit on oscillation time τnn′>12.0 s at 95% C.L. B′ between 0 12.5 μT.Received 26 May 2009DOI:https://doi.org/10.1103/PhysRevD.80.032003©2009 American Physical Society
The measurement of the neutron electric dipole moment (nEDM) constrains contribution CP-violating terms within both Standard Model and its extensions. experiment uses ultracold neutrons (UCN) stored in vacuum at room temperature. This technique provided last (and best) limit by RAL/Sussex/ILL collaboration 2006: dn < 2:9 × 10-26 e cm (90% C.L.). We aim to improve experimental sensitivity a factor 5 2-3 years, using an upgrade same apparatus. will take advantage increased density Paul...
We present a theoretical and experimental study of the resonant circularly-polarized-light-induced Hanle effect in ground state Cs vapor atoms paraffin-coated cell. The manifests itself as narrow resonance (centered at $B=0$) dependence optical transmission coefficient on magnitude an external magnetic field $\stackrel{P\vec}{B}$. develop model that yields algebraic expression for shape these resonances arbitrary orientations angular momenta states coupled by exciting light, provided light...
This roadmap bundles fast developing topics in experimental optical quantum sciences, addressing current challenges as well potential advances future research. We have focused on three main areas: assisted high precision measurements, information/simulation, and gases. Quantum measurements are discussed the first sections, which review clocks, atom interferometry, magnetometry. These fields already successfully utilized various applied areas. will discuss approaches to extend this impact...
We present a magnetometer based on optically pumped Cs atoms that measures the magnitude and direction of 1 μT magnetic field. Multiple circularly polarized laser beams were used to probe free spin precession atoms. The design was optimized for long-time stability achieves scalar resolution better than 300 fT integration times ranging from 80 ms 1000 s. best less reached with 1.6 6 able measure field 10 μrad s up 2000