47 research outputs found
Testing the universality of free fall with rubidium and ytterbium in a very large baseline atom interferometer
We propose a very long baseline atom interferometer test of Einstein's
equivalence principle (EEP) with ytterbium and rubidium extending over 10m of
free fall. In view of existing parametrizations of EEP violations, this choice
of test masses significantly broadens the scope of atom interferometric EEP
tests with respect to other performed or proposed tests by comparing two
elements with high atomic numbers. In a first step, our experimental scheme
will allow reaching an accuracy in the E\"otv\"os ratio of .
This achievement will constrain violation scenarios beyond our present
knowledge and will represent an important milestone for exploring a variety of
schemes for further improvements of the tests as outlined in the paper. We will
discuss the technical realisation in the new infrastructure of the Hanover
Institute of Technology (HITec) and give a short overview of the requirements
to reach this accuracy. The experiment will demonstrate a variety of techniques
which will be employed in future tests of EEP, high accuracy gravimetry and
gravity-gradiometry. It includes operation of a force sensitive atom
interferometer with an alkaline earth like element in free fall, beam splitting
over macroscopic distances and novel source concepts
Reply to Comment on 'Species-selective lattice launch for precision atom interferometry'
Reply to: Alexander D Cronin and Raisa Trubko: Comment on 'Species-selective lattice launch for precision atom interferometry'. In: New Journal of Physics 18 (2016), Nr. 11, 118001. DOI: https://doi.org/10.1088/1367-2630/18/11/11800
Species-selective lattice launch for precision atom interferometry
Long-baseline precision tests based on atom interferometry require drastic control over the initial external degrees of freedom of atomic ensembles to reduce systematic effects. The use of optical lattices (OLs) is a highly accurate method to manipulate atomic states in position and momentum allowing excellent control of the launch in atomic fountains. The simultaneous lattice launch of two atomic species, as required in a quantum test of the equivalence principle, is however problematic due to crosstalk effects. In this article, we propose to selectively address two species of alkalines by applying two OLs at or close to magic-zero wavelengths of the atoms. The proposed scheme applies in general for a pair of species with a vastly different ac Stark shift to a laser wavelength. We illustrate the principle by studying a fountain launch of condensed ensembles of 87Rb and 41K initially co-located. Numerical simulations confirm the fidelity of our scheme up to few nm and nm sâ1 in inter-species differential position and velocity, respectively. This result is a pre-requisite for the next performance level in precision tests.DAADDFG/SFB/geo-QDLR/50WM1131-1137Federal Ministry of Economic affairs and Energy (BMWi
Universal atom interferometer simulation of elastic scattering processes
In this article, we introduce a universal simulation framework covering all regimes of matter-wave light-pulse elastic scattering. Applied to atom interferometry as a study case, this simulator solves the atom-light diffraction problem in the elastic case, i.e., when the internal state of the atoms remains unchanged. Taking this perspective, the light-pulse beam splitting is interpreted as a space and time-dependent external potential. In a shift from the usual approach based on a system of momentum-space ordinary differential equations, our position-space treatment is flexible and scales favourably for realistic cases where the light fields have an arbitrary complex spatial behaviour rather than being mere plane waves. Moreover, the solver architecture we developed is effortlessly extended to the problem class of trapped and interacting geometries, which has no simple formulation in the usual framework of momentum-space ordinary differential equations. We check the validity of our model by revisiting several case studies relevant to the precision atom interferometry community. We retrieve analytical solutions when they exist and extend the analysis to more complex parameter ranges in a cross-regime fashion. The flexibility of the approach, the insight it gives, its numerical scalability and accuracy make it an exquisite tool to design, understand and quantitatively analyse metrology-oriented matter-wave interferometry experiments. © 2020, The Author(s)
A high-flux BEC source for mobile atom interferometers
Quantum sensors based on coherent matter-waves are precise measurement
devices whose ultimate accuracy is achieved with Bose-Einstein condensates
(BEC) in extended free fall. This is ideally realized in microgravity
environments such as drop towers, ballistic rockets and space platforms.
However, the transition from lab-based BEC machines to robust and mobile
sources with comparable performance is a challenging endeavor. Here we report
on the realization of a miniaturized setup, generating a flux of quantum degenerate Rb atoms every 1.6s. Ensembles of atoms can be produced at a 1Hz rate. This is achieved by loading a
cold atomic beam directly into a multi-layer atom chip that is designed for
efficient transfer from laser-cooled to magnetically trapped clouds. The
attained flux of degenerate atoms is on par with current lab-based BEC
experiments while offering significantly higher repetition rates. Additionally,
the flux is approaching those of current interferometers employing Raman-type
velocity selection of laser-cooled atoms. The compact and robust design allows
for mobile operation in a variety of demanding environments and paves the way
for transportable high-precision quantum sensors.Comment: 22 pages, 6 figure
Precision inertial sensing with quantum gases
Quantum sensors based on light-pulse atom interferometers allow for
high-precision measurements of inertial and electromagnetic forces such as the
accurate determination of fundamental constants as the fine structure constant
or testing foundational laws of modern physics as the equivalence principle.
These schemes unfold their full performance when large interrogation times
and/or large momentum transfer can be implemented. In this article, we
demonstrate how precision interferometry can benefit from the use of
Bose-Einstein condensed sources when the state of the art is challenged. We
contrast systematic and statistical effects induced by Bose-Einstein condensed
sources with thermal sources in three exemplary science cases of Earth- and
space-based sensors.Comment: 13 page
Twin-lattice atom interferometry
Inertial sensors based on cold atoms have great potential for navigation,
geodesy, or fundamental physics. Similar to the Sagnac effect, their
sensitivity increases with the space-time area enclosed by the interferometer.
Here, we introduce twin-lattice atom interferometry exploiting Bose-Einstein
condensates. Our method provides symmetric momentum transfer and large areas in
palm-sized sensor heads with a performance similar to present meter-scale
Sagnac devices
Axion-like-particle search with high-intensity lasers
We study ALP-photon-conversion within strong inhomogeneous electromagnetic
fields as provided by contemporary high-intensity laser systems. We observe
that probe photons traversing the focal spot of a superposition of Gaussian
beams of a single high-intensity laser at fundamental and frequency-doubled
mode can experience a frequency shift due to their intermittent propagation as
axion-like-particles. This process is strongly peaked for resonant masses on
the order of the involved laser frequencies. Purely laser-based experiments in
optical setups are sensitive to ALPs in the mass range and can
thus complement ALP searches at dipole magnets.Comment: 25 pages, 2 figure
Interacting quantum mixtures for precision atom interferometry
We present a source engineering concept for a binary quantum mixture suitable as input for differential, precision atom interferometry with drift times of several seconds. To solve the non-linear dynamics of the mixture, we develop a set of scaling approach equations and verify their validity contrasting it to the one of a system of coupled Gross-Pitaevskii equations. This scaling approach is a generalization of the standard approach commonly used for single species. Its validity range is discussed with respect to intra- and inter-species interaction regimes. We propose a multi-stage, non-linear atomic lens sequence to simultaneously create dual ensembles with ultra-slow kinetic expansion energies, below 15 pK. Our scheme has the advantage of mitigating wave front aberrations, a leading systematic effect in precision atom interferometry