Interferometry with Bose-Einstein Condensates in Microgravity

Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation of the wave nature of matter. Due to their unique coherence properties, Bose-Einstein condensates are ideal sources for an atom interferometer in extended free fall. In this paper we report on the realization of an asymmetric Mach-Zehnder interferometer operated with a Bose-Einstein condensate in microgravity. The resulting interference pattern is similar to the one in the far-field of a double-slit and shows a linear scaling with the time the wave packets expand. We employ delta-kick cooling in order to enhance the signal and extend our atom interferometer. Our experiments demonstrate the high potential of interferometers operated with quantum gases for probing the fundamental concepts of quantum mechanics and general relativity.Comment: 8 pages, 3 figures; 8 pages of supporting materia

Atom-Chip Fountain Gravimeter

We demonstrate a quantum gravimeter by combining the advantages of an atom chip for the generation, delta-kick collimation, and coherent manipulation of freely falling Bose-Einstein condensates (BECs) with an innovative launch mechanism based on Bloch oscillations and double Bragg diffraction. Our high-contrast BEC interferometer realizes tens of milliseconds of free fall in a volume as little as a one centimeter cube and paves the way for measurements with sub-μGal accuracies in miniaturized, robust devices

Double Bragg interferometry

We employ light-induced double Bragg diffraction of delta-kick collimated Bose-Einstein condensates to create three symmetric Mach-Zehnder interferometers. They rely on (i) first-order, (ii) two successive first-order, and (iii) second-order processes which demonstrate the scalability of the corresponding momentum transfer. With respect to devices based on conventional Bragg scattering, these symmetric interferometers double the scale factor and feature a better suppression of noise and systematic uncertainties intrinsic to the diffraction process. Moreover, we utilize these interferometers as tiltmeters for monitoring their inclination with respect to gravity

Space-borne Bose-Einstein condensation for precision interferometry

Space offers virtually unlimited free-fall in gravity. Bose-Einstein condensation (BEC) enables ineffable low kinetic energies corresponding to pico- or even femtokelvins. The combination of both features makes atom interferometers with unprecedented sensitivity for inertial forces possible and opens a new era for quantum gas experiments. On January 23, 2017, we created Bose-Einstein condensates in space on the sounding rocket mission MAIUS-1 and conducted 110 experiments central to matter-wave interferometry. In particular, we have explored laser cooling and trapping in the presence of large accelerations as experienced during launch, and have studied the evolution, manipulation and interferometry employing Bragg scattering of BECs during the six-minute space flight. In this letter, we focus on the phase transition and the collective dynamics of BECs, whose impact is magnified by the extended free-fall time. Our experiments demonstrate a high reproducibility of the manipulation of BECs on the atom chip reflecting the exquisite control features and the robustness of our experiment. These properties are crucial to novel protocols for creating quantum matter with designed collective excitations at the lowest kinetic energy scales close to femtokelvins.Comment: 6 pages, 4 figure

A Model-driven Software Architecture for Ultra-cold Gas Experiments in Space

Developing software for large and complex experiments is a challenging task. It must incorporate many requirements from different domains, all with their own conceptions about the overall systems. An additional level of complexity is added if the experiment is conducted autonomously during a sounding rocket flight. Without a proper software architecture and development techniques, achieving and maintaining a high code quality is a very cumbersome task. This paper describes the architecture and the model-driven development approach we used to implement the control software of the experiments in the MAIUS-1 mission (matter-wave interferometry in microgravity). In this mission, the software had to handle around 150 experiments in six minutes autonomously and adapt to changes in the control flow according to real-time data from the experiment. The MAIUS-1 mission was the first mission to create Bose-Einstein condensates in space and conduct other experiments with ultra-cold gases on a sounding rocket. Besides the scientific goals in the area of quantum-optics, other important objectives of the mission were the miniaturization and further development of laser systems, vacuum components, optical sensors, and other related technologies. To fulfil these goals, new experimental hardware has been created which had to be integrated and tested with the software of the experiment computer. The custom-made hardware and the considerable number of domains involved brought up many challenges for the software engineering. To face all these challenges of developing software with this high complexity, we chose to follow a model-driven software development approach. Several domain-specific languages (DSLs) accompanied with specialized tools were created to allow the physicists and electronic engineers to describe system components and the experiments in a domain-specific way. These descriptions were then automatically transformed in C++ code for the flight software. This way we could actively incorporate all the domains involved in conducting the experiment directly in building the flight software without compromising the software quality. We created a versatile software platform not only for the MAIUS-1 mission but also for upcoming missions with similar experiments and hardware. With our approach we were able to generate around 84% of the source code for the final flight software from the domain-specific models. Besides the improvement of the development process, the code generation made a significant contribution to the overall software quality as almost all manual coding of error-prone boilerplate code could be mitigated

SECAMP - Student Experiments with Cold Atoms on Micro- and Hypergravity Platforms

The QUANTUS consortium started activities to perform atom interferometry on a sounding rocket in the year 2011. Three sounding rocket missions (MAIUS-1 to 3) have been planned to demonstrate Bose-Einstein condensation and atom interferometry with rubidium and potassium atoms. Two different payloads MAIUS-A and MAIUS-B are being designed, qualified and integrated in the time frame from 2011 until 2020. Based on this heritage the “Student Experiments with Cold Atoms for Microgravity Platforms” (SECAMP) project has been started at the University of Bremen. The scope of the project is to design and built a payload for student experiments with cold atoms on multiple micro-gravity and hyper-gravity platforms. The apparatus shall allow the generation of a molasses of Rubidium-87 atoms and observation of the cooled atoms through fluorescence imaging in three perpendicular axes. This will enable detecting the movement of the atoms due to (residual) accelerations once the magneto-optical trap is switched off. As such the setup will form a simple accelerometer. The payload shall be designed to be suitable for operation on hyperbolic flights, the drop tower, sounding rockets and centrifuges allowing the participants to apply for the manifold national and European student programs on these platforms. This talk will give an overview on the current design and the requirements imposed by the different platforms. Moreover the student team and their role in the project will be presented and the current status of the project will be highlighted

SECAMP - Student Experiments with Cold Atoms on Micro- and Hypergravity Platforms

The QUANTUS consortium started activities to perform atom interferometry on a sounding rocket in the year 2011. Three sounding rocket missions (MAIUS-1 to 3) have been planned to demonstrate Bose-Einstein condensation and atom interferometry with rubidium and potassium atoms. Two different payloads MAIUS-A and MAIUS-B are being designed, qualified and integrated in the time frame from 2011 until 2020. Based on this heritage the “Student Experiments with Cold Atoms for Microgravity Platforms” (SECAMP) project has been started at the University of Bremen. The scope of the project is to design and built a payload for student experiments with cold atoms on multiple micro-gravity and hyper-gravity platforms. The apparatus shall allow the generation of a molasses of Rubidium-87 atoms and observation of the cooled atoms through fluorescence imaging in three perpendicular axes. This will enable detecting the movement of the atoms due to (residual) accelerations once the magneto-optical trap is switched off. As such the setup will form a simple accelerometer. The payload shall be designed to be suitable for operation on hyperbolic flights, the drop tower, sounding rockets and centrifuges allowing the participants to apply for the manifold national and European student programs on these platforms. This talk will give an overview on the current design and the requirements imposed by the different platforms. Moreover the student team and their role in the project will be presented and the current status of the project will be highlighted