arXiv subjects

E. M. Rasel

Publications and source records attributed to E. M. Rasel.

At least 19 recordsLinked to original sources

arXiv2026

Optomechanical inertial reference for atom interferometry

Atom interferometers are among the most sensitive inertial sensors, yet deployment outside the laboratory is limited by vibration noise, conventionally mitigated by external sensors or bulky isolation. Here we demonstrate a hybrid inertial sensor which fuses an optomechanical resonator and an atom interferometer by exploiting the resonator's test mass as the interferometer's reference mirror. This allows for better correlation than with two separate sensors, whose unknown transfer function is replaced by the static response of one mechanical element. The resonator achieves a displacement sensitivity of $8.6\cdot 10^{-15}$ m/$\sqrt{\mathrm{Hz}}$ with suppressed 1/f noise and yields a minimum acceleration sensitivity of $1.1\cdot10^{-6}$ m/s$^2$/$\sqrt{\mathrm{Hz}}$ over a bandwidth extending from sub-Hertz to 2.5 kHz. Under ambient laboratory conditions the integrated system removes vibration-induced phase ambiguity for accelerations up to $50\cdot 10^{-3}$ m/s$^2$ and reaches the interferometer's technical noise limit, which a commercial force-balance accelerometer does not. Because the resonance-tracking readout is largely independent of the mechanical design, the architecture transfers directly to other precision sensing platforms.

quant-ph↗

arXiv2026

INTENTAS -- An entanglement-enhanced atomic sensor for microgravity

The INTENTAS project aims to develop an atomic sensor utilizing entangled Bose-Einstein condensates (BECs) in a microgravity environment. This key achievement is necessary to advance the capability for measurements that benefit from both entanglement-enhanced sensitivities and extended interrogation times. The project addresses significant challenges related to size, weight, and power management (SWaP) specific to the experimental platform at the Einstein-Elevator in Hannover. The design ensures a low-noise environment essential for the creation and detection of entanglement. Additionally, the apparatus features an innovative approach to the all-optical creation of BECs, providing a flexible system for various configurations and meeting the requirements for rapid turnaround times. Successful demonstration of this technology in the Einstein-Elevator will pave the way for a future deployment in space, where its potential applications will unlock high-precision quantum sensing.

physics.ins-det↗

arXiv2025

Multi-axis inertial sensing with 2D matter-wave arrays

Atom interferometery is an exquisite measurement technique sensitive to inertial forces. However, it is commonly limited to a single sensitive axis, allowing high-precision multi-dimensional sensing only through subsequent or post-corrected measurements. We report on a novel method for multi-axis inertial sensing based on the correlation of simultaneous light-pulse atom interferometers in 2D array arrangements of Bose-Einstein Condensates (BEC). Deploying a scalable 3 x 3 BEC array spanning 1.6 mm^2 created using time-averaged optical potentials, we perform measurements of linear acceleration induced by gravity and simultaneously demonstrate sensitivity to angular velocity and acceleration of a rotating reference mirror, as well as gravity gradients and higher-order derivatives. Our work enables simple, high-precision multi-axis inertial sensing compatible with high rotation rates, e.g., for inertial navigation in dynamic environments. We finally envision further applications of our method, e.g., 3D in-situ measurements and reconstruction of laser beam intensities and wave fronts.

physics.atom-ph↗

arXiv2022

All-Optical Matter-Wave Lens using Time-Averaged Potentials

The stability of matter-wave sensors benefits from interrogating large-particle-number atomic ensembles at high cycle rates. The use of quantum-degenerate gases with their low effective temperatures allows constraining systematic errors towards highest accuracy, but their production by evaporative cooling is costly with regard to both atom number and cycle rate. In this work, we report on the creation of cold matter-waves using a crossed optical dipole trap and shaping it by means of an all-optical matter-wave lens. We demonstrate the trade off between residual kinetic energy and atom number by short-cutting evaporative cooling and estimate the corresponding performance gain in matter-wave sensors. Our method is implemented using time-averaged optical potentials and hence easily applicable in optical dipole trapping setups.

physics.atom-ph↗

arXiv2020

Optomechanical resonator-enhanced atom interferometry

Matter-wave interferometry and spectroscopy of optomechanical resonators offer complementary advantages. Interferometry with cold atoms is employed for accurate and long-term stable measurements, yet it is challenged by its dynamic range and cyclic acquisition. Spectroscopy of optomechanical resonators features continuous signals with large dynamic range, however it is generally subject to drifts. In this work, we combine the advantages of both devices. Measuring the motion of a mirror and matter waves interferometrically with respect to a joint reference allows us to operate an atomic gravimeter in a seismically noisy environment otherwise inhibiting readout of its phase. Our method is applicable to a variety of quantum sensors and shows large potential for improvements of both elements by quantum engineering.

physics.optics↗

arXiv2020

A robust, high-flux source of laser-cooled ytterbium atoms

We present a high-flux source of cold ytterbium atoms that is robust, lightweight and low-maintenance. Our apparatus delivers $10^9$ atoms/s into a 3D magneto-optical trap without requiring water-cooling or high current power supplies. We achieve this by employing a Zeeman slower and a 2D magneto-optical trap fully based on permanent magnets in Halbach configurations. This strategy minimizes mechanical complexity, stray magnetic fields, and heat production while requiring little to no maintenance, making it applicable to both embedded systems that seek to minimize electrical power consumption, and large scale experiments to reduce the complexity of their subsystems.

physics.atom-ph↗

arXiv2020

Technologies for the ELGAR large scale atom interferometer array

We proposed the European Laboratory for Gravitation and Atom-interferometric Research (ELGAR), an array of atom gradiometers aimed at studying space-time and gravitation with the primary goal of observing gravitational waves (GWs) in the infrasound band with a peak strain sensitivity of $3.3 \times 10^{-22}/\sqrt{\text{Hz}}$ at 1.7 Hz. In this paper we detail the main technological bricks of this large scale detector and emphasis the research pathways to be conducted for its realization. We discuss the site options, atom optics, and source requirements needed to reach the target sensitivity. We then discuss required seismic isolation techniques, Gravity Gradient Noise reduction strategies, and the metrology of various noise couplings to the detector.

physics.atom-ph↗

arXiv2020

Quantum test of the Universality of Free Fall using rubidium and potassium

We report on an improved test of the Universality of Free Fall using a rubidium-potassium dual-species matter wave interferometer. We describe our apparatus and detail challenges and solutions relevant when operating a potassium interferometer, as well as systematic effects affecting our measurement. Our determination of the Eötvös ratio yields $η_{\,\text{Rb,K}}=-1.9\times10^{-7}$ with a combined standard uncertainty of $σ_η=3.2\times10^{-7}$.

physics.atom-ph↗

arXiv2020

A scalable high-performance magnetic shield for Very Long Baseline Atom Interferometry

We report on the design, construction, and characterization of a 10 m-long high-performance magnetic shield for Very Long Baseline Atom Interferometry (VLBAI). We achieve residual fields below 4 nT and longitudinal inhomogeneities below 2.5 nT/m over 8 m along the longitudinal direction. Our modular design can be extended to longer baselines without compromising the shielding performance. Such a setup constrains biases associated with magnetic field gradients to the sub-pm/$\textrm{s}^2$ level in atomic matterwave accelerometry with rubidium atoms and paves the way towards tests of the universality of free fall with atomic test masses beyond the $10^{-13}$ level.

physics.ins-det↗

arXiv2019

Matter Wave Interferometry for Inertial Sensing and Tests of Fundamental Physics

Very Long Baseline Atom Interferometry (VLBAI) corresponds to ground-based atomic matter-wave interferometry on large scales in space and time, letting the atomic wave functions interfere after free evolution times of several seconds or wave packet separation at the scale of meters. As inertial sensors, e.g., accelerometers, these devices take advantage of the quadratic scaling of the leading order phase shift with the free evolution time to enhance their sensitivity, giving rise to compelling experiments. With shot noise-limited instabilities better than $10^{-9}$ m/s$^2$ at 1 s at the horizon, VLBAI may compete with state-of-the-art superconducting gravimeters, while providing absolute instead of relative measurements. When operated with several atomic states, isotopes, or species simultaneously, tests of the universality of free fall at a level of parts in $10^{13}$ and beyond are in reach. Finally, the large spatial extent of the interferometer allows one to probe the limits of coherence at macroscopic scales as well as the interplay of quantum mechanics and gravity. We report on the status of the VLBAI facility, its key features, and future prospects in fundamental science.

physics.atom-ph↗

arXiv2019

Scalable, symmetric atom interferometer for infrasound gravitational wave detection

We propose a terrestrial detector for gravitational waves with frequencies between 0.3 Hz and 5 Hz. Therefore, we discuss a symmetric matter-wave interferometer with a single loop and a folded triple-loop geometry. The latter eliminates the need for atomic ensembles at femtokelvin energies imposed by the Sagnac effect in other atom interferometric detectors. It also combines several advantages of current vertical and horizontal matter wave antennas and enhances the scalability in order to achieve a peak strain sensitivity of $2\cdot10^{-21}\,/\sqrt{\mathrm{Hz}}$.

quant-ph↗

arXiv2019

T^3-Stern-Gerlach Matter-Wave Interferometer

We present a unique matter-wave interferometer whose phase scales with the cube of the time the atom spends in the interferometer. Our scheme is based on a full-loop Stern-Gerlach interferometer incorporating four magnetic field gradient pulses to create a state-dependent force. In contrast to typical atom interferometers which make use of laser light for the splitting and recombination of the wave packets, this realization uses no light and can therefore serve as a high-precision surface probe at very close distances.

quant-ph↗

arXiv2019

Optimal control of the transport of Bose-Einstein condensates with atom chips

Using Optimal Control Theory (OCT), we design fast ramps for the controlled transport of Bose-Einstein condensates with atom chips' magnetic traps. These ramps are engineered in the context of precision atom interferometry experiments and support transport over large distances, typically of the order of 1 mm, i.e. about 1,000 times the size of the atomic clouds, yet with durations not exceeding 200 ms. We show that with such transport durations of the order of the trap period, one can recover the ground state of the final trap at the end of the transport. The performance of the OCT procedure is compared to that of a Shortcut-To-Adiabaticity (STA) protocol and the respective advantages / disadvantages of the OCT treatment over the STA one are discussed.

quant-ph↗

arXiv2017

Fast manipulation of Bose-Einstein condensates with an atom chip

We present a detailed theoretical analysis of the implementation of shortcut-to-adiabaticity protocols for the fast transport of neutral atoms with atom chips. The objective is to engineer transport ramps with durations not exceeding a few hundred milliseconds to provide metrologically-relevant input states for an atomic sensor. Aided by numerical simulations of the classical and quantum dynamics, we study the behavior of a Bose-Einstein condensate in an atom chip setup with realistic anharmonic trapping. We detail the implementation of fast and controlled transports over large distances of several millimeters, i.e. distances 1000 times larger than the size of the atomic cloud. A subsequent optimized release and collimation step demonstrates the capability of our transport method to generate ensembles of quantum gases with expansion speeds in the picokelvin regime. The performance of this procedure is analyzed in terms of collective excitations reflected in residual center of mass and size oscillations of the condensate. We further evaluate the robustness of the protocol against experimental imperfections.

quant-ph↗

arXiv2016

$T^3$-interferometer for atoms

The quantum mechanical propagator of a massive particle in a linear gravitational potential derived already in 1927 by Earle H. Kennard \cite{Kennard,Kennard2} contains a phase that scales with the third power of the time $T$ during which the particle experiences the corresponding force. Since in conventional atom interferometers the internal atomic states are all exposed to the same acceleration $a$, this $T^3$-phase cancels out and the interferometer phase scales as $T^2$. In contrast, by applying an external magnetic field we prepare two different accelerations $a_1$ and $a_2$ for two internal states of the atom, which translate themselves into two different cubic phases and the resulting interferometer phase scales as $T^3$. We present the theoretical background for, and summarize our progress towards experimentally realizing such a novel atom interferometer.

quant-ph↗

arXiv2015

Towards a Mg lattice clock: Observation of the $^1S_{0}-$$^3P_{0}$ transition and determination of the magic wavelength

We optically excite the electronic state $3s3p~^3P_{0}$ in $^{24}$Mg atoms, laser-cooled and trapped in a magic-wavelength lattice. An applied magnetic field enhances the coupling of the light to the otherwise strictly forbidden transition. We determine the magic wavelength, the quadratic magnetic Zeeman shift and the transition frequency to be 468.463(207)$\,$nm, -206.6(2.0)$\,$MHz/T$^2$ and 655 058 646 691(101)$\,$kHz, respectively. These are compared with theoretical predictions and results from complementary experiments. We also developed a high-precision relativistic structure model for magnesium, give an improved theoretical value for the blackbody radiation shift and discuss a clock based on bosonic magnesium.

physics.atom-ph↗

arXiv2015

Ground Tests of Einstein's Equivalence Principle: From Lab-based to 10-m Atomic Fountains

To date, no framework combining quantum field theory and general relativity and hence unifying all four fundamental interactions, exists. Violations of the Einstein's equivalence principle (EEP), being the foundation of general relativity, may hold the key to a theory of quantum gravity. The universality of free fall (UFF), which is one of the three pillars of the EEP, has been extensively tested with classical bodies. Quantum tests of the UFF, e.g. by exploiting matter wave interferometry, allow for complementary sets of test masses, orders of magnitude larger test mass coherence lengths and investigation of spin-gravity coupling. We review our recent work towards highly sensitive matter wave tests of the UFF on ground. In this scope, the first quantum test of the UFF utilizing two different chemical elements, Rb-87 and K-39, yielding an Eötvös ratio $η_{\,\text{Rb,K}}=(0.3\pm 5.4)\times 10^{-7}$ has been performed. We assess systematic effects currently limiting the measurement at a level of parts in $10^8$ and finally present our strategies to improve the current state-of-the-art with a test comparing the free fall of rubidium and ytterbium in a very long baseline atom interferometry setup. Here, a 10 m baseline combined with a precise control of systematic effects will enable a determination of the Eötvös ratio at a level of parts in $10^{13}$ and beyond, thus reaching and overcoming the performance limit of the best classical tests.

physics.atom-ph↗

arXiv2013

Differential atom interferometry with $^{87}$Rb and $^{85}$Rb for testing the UFF in STE-QUEST

In this paper we discuss in detail an experimental scheme to test the universality of free fall (UFF) with a differential $^{87}$Rb / $^{85}$Rb atom interferometer applicable for extended free fall of several seconds in the frame of the STE-QUEST mission. This analysis focuses on suppression of noise and error sources which would limit the accuracy of a violation measurement. We show that the choice of atomic species and the correctly matched parameters of the interferometer sequence are of utmost importance to suppress leading order phase shifts. In conclusion we will show the expected performance of $2$ parts in $10^{15}$ of such an interferometer for a test of the UFF.

physics.atom-ph↗