A5001028173- Advanced Frequency and Time Standards
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Quantum Mechanics and Applications
- Noncommutative and Quantum Gravity Theories
- Geophysics and Sensor Technology
- Laser Design and Applications
- Relativity and Gravitational Theory
- Photonic and Optical Devices
- Scientific Measurement and Uncertainty Evaluation
- Solid State Laser Technologies
- Pulsars and Gravitational Waves Research
- Advanced Measurement and Metrology Techniques
- Cosmology and Gravitation Theories
- Mechanical and Optical Resonators
- Semiconductor Lasers and Optical Devices
- Black Holes and Theoretical Physics
- Radioactive Decay and Measurement Techniques
- Photorefractive and Nonlinear Optics
- Adaptive optics and wavefront sensing
- Geophysics and Gravity Measurements
- Quantum Information and Cryptography
- Experimental and Theoretical Physics Studies
Humboldt State University
2007-2024
Humboldt-Universität zu Berlin
2014-2023
Ferdinand-Braun-Institut
2010-2021
Kirchhoff (Germany)
2010-2017
Institute for Physics
2014
University of Bremen
2013
Dornier Flugzeugwerke (Germany)
2006
HTWG Hochschule Konstanz - Technik, Wirtschaft und Gestaltung
2006
University of Florence
2006
University of Konstanz
1999-2005
We have built an atom interferometer that can measure g, the local acceleration due to gravity, with a resolution of Δg/g = 2 × 10−8 after single 1.3 s measurement cycle, 3 10−9 1 min and 10−10 two days integration time. The difference between our value for g one obtained by falling corner-cube optical is (7 ± 7) g. uses velocity-selective stimulated Raman transitions laser-cooled caesium atoms in atomic fountain. extend previous methods analysing include effects gravitational gradient. also...
Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation the wave nature matter. Because their unique coherence properties, Bose-Einstein condensates ideal sources for an atom interferometer in extended free fall. In this Letter we report on realization asymmetric Mach-Zehnder operated with condensate microgravity. The resulting interference pattern is similar to one far field double slit and shows linear scaling time packets expand. We employ...
Abstract We propose in this White Paper a concept for space experiment using cold atoms to search ultra-light dark matter, and detect gravitational waves the frequency range between most sensitive ranges of LISA terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment Dark Matter Gravity Exploration (AEDGE), will also complement other planned searches exploit synergies with wave detectors. give examples extended sensitivity matter offered...
Albert Einstein's insight that it is impossible to distinguish a local experiment in "freely falling elevator" from one free space led the development of theory general relativity. The wave nature matter manifests itself striking way Bose-Einstein condensates, where millions atoms lose their identity and can be described by single macroscopic function. We combine these two topics report preparation observation condensate during fall 146-meter-tall evacuated drop tower. During expansion over...
Changes of surface gravity on Earth are great interest in geodesy, earth sciences and natural resource exploration. They indicative system's mass redistributions vertical motion, usually measured with falling corner-cube- superconducting gravimeters (FCCG SCG). Here we report absolute measurements a mobile quantum gravimeter based atom interferometry. The were conducted Germany Sweden over periods several days simultaneous SCG FCCG comparisons. show the best-reported performance atomic to...
Precision time references in space are of major importance to satellite-based fundamental science, global satellite navigation, earth observation, and formation flying.Here we report on the operation a compact, rugged, automated optical frequency comb setup sounding rocket under microgravity.The experiment compared two clocks, one based D 2 transition Rb, another hyperfine splitting Cs.This represents first clock space, which is an important milestone for future precision metrology.Based...
The theory of general relativity describes macroscopic phenomena driven by the influence gravity while quantum mechanics brilliantly accounts for microscopic effects.Despite their tremendous individual success, a complete unification fundamental interactions is missing and remains one most challenging important quests in modern theoretical physics.The STE-QUEST satellite mission, proposed as medium-size mission within Cosmic Vision program European Space Agency (ESA), aims testing with high...
We report on a new test of Lorentz invariance performed by comparing the resonance frequencies two orthogonal cryogenic optical resonators subject to Earth's rotation over $\ensuremath{\sim}1\text{ }\mathrm{y}\mathrm{r}$. For possible anisotropy speed light $c$, we obtain ${\ensuremath{\Delta}}_{\ensuremath{\theta}}c/{c}_{0}=(2.6\ifmmode\pm\else\textpm\fi{}1.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}$. Within Robertson-Mansouri-Sexl (RMS) theory, this implies an isotropy...
We present an improved laboratory test of Lorentz invariance in electrodynamics by testing the isotropy speed light. Our measurement compares resonance frequencies two orthogonal optical resonators that are implemented a single block fused silica and rotated continuously on precision air bearing turntable. An analysis data recorded over course one year sets limit anisotropy light \Delta c/c ~ 1 x 10^{-17}. This constitutes most accurate $c$ to date allows constrain parameters violating...
We investigate leading order deviations from general relativity that violate the Einstein equivalence principle in gravitational standard model extension. show redshift experiments based on matter waves and clock comparisons are equivalent to one another. Consideration of torsion balance tests, along with wave, microwave, optical, M\"ossbauer yields comprehensive limits spin-independent principle-violating extension terms at $10^{-6}$ level.
Do the laws of quantum physics still hold for macroscopic objects - this is at heart Schrödinger's cat paradox or do gravitation yet unknown effects set a limit massive particles? What fundamental relation between and gravity? Ground-based experiments addressing these questions may soon face limitations due to limited free-fall times quality vacuum microgravity. The proposed mission Macroscopic Quantum Resonators (MAQRO) overcome allow such questions. MAQRO harnesses recent developments in...
In contrast to light, matter-wave optics of quantum gases deals with interactions even in free space and for ensembles comprising millions atoms. We exploit these a degenerate gas as an adjustable lens coherent atom optics. By combining interaction-driven quadrupole-mode excitation Bose-Einstein condensate (BEC) magnetic lens, we form time-domain system. The focus is tuned by the strength lensing potential oscillatory phase quadrupole mode. placing at infinity, lower total internal kinetic...
We report relativity tests based on data from two simultaneous Michelson-Morley experiments, spanning a period of more than 1 yr. Both were actively rotated turntables. One (in Berlin, Germany) uses optical Fabry-Perot resonators made fused silica; the other Perth, Australia) microwave whispering-gallery sapphire resonators. Within standard model extension, we obtain limits Lorentz violation for electrons (5 coefficients) and photons (8) at levels down to ${10}^{\ensuremath{-}16}$, improved...
We report on a test of Lorentz invariance performed by comparing the resonance frequencies one stationary optical resonator and continuously rotating precision air bearing turntable. Special attention is paid to control rotation induced systematic effects. Within photon sector standard model extension, we obtain improved limits combinations 8 parameters at level few parts in ${10}^{\ensuremath{-}16}$. For previously least well known parameter find...
Quantum sensors based on coherent matter-waves are precise measurement devices whose ultimate accuracy is achieved with Bose–Einstein condensates (BECs) in extended free fall. This ideally realized microgravity environments such as drop towers, ballistic rockets and space platforms. However, the transition from lab-based BEC machines to robust mobile sources comparable performance a challenging endeavor. Here we report realization of miniaturized setup, generating flux quantum degenerate...
Abstract Lorentz symmetry is a foundational property of modern physics, underlying the standard model particles and general relativity. It anticipated that these two theories are low-energy approximations single theory unified consistent at Planck scale. Many unifying proposals allow to be broken, with observable effects appearing Planck-suppressed levels; thus, precision tests invariance needed assess guide theoretical efforts. Here we use ultrastable oscillator frequency sources perform...