QUANTENINERIAL MEASURING UNIT AND METHOD FOR DETECTING AT LEAST ONE PHYSICAL MEASURING QUANTITY

Description

[0001] The invention relates to a quantum inertial measurement unit for detecting at least one physical quantity based on atom interferometric acceleration measurement. The invention further relates to a method for detecting at least one physical quantity based on atom interferometric acceleration measurement using such a quantum inertial measurement unit.

[0002] One-dimensional atom interferometric acceleration measurements with cold atoms are already well-known in the art. There are also proposals to extend such atom interferometric measurements to multiple spatial directions and additional measurands, in particular angular velocity, angular acceleration, etc. However, these proposals [1, 2, 3, 4, 5, 6, 7] involve considerably increased instrumental effort compared to one-dimensional acceleration measurements. In some cases, complex approaches for the simultaneous measurement of multiple quantities and axes [6, 7] are proposed.

[0003] GERSEMANN ET AL: "Differential interferometry using a Bose-Einstein condensate", THE EUROPEAN PHYSICAL JOURNAL D, SPRINGER BERLIN HEIDELBERG, BERLIN / HEIDELBERG, Vol. 74, No. 10, October 1, 2020 (2020-10-01), ISSN: 1434-6060, DOI: 10.1140 / EPJD / E2020-10417-8 describes a Mach-Zehnder atom interferometer in which a Bose-Einstein condensate (BEC) is first trapped in an atom trap and then split into two matter wave packets that drift apart. Using a dual interferometer, the phases of the two wave packets are measured, and the acceleration and angular velocity of the BEC are derived from these measurements.

[0004] The invention is based on the objective of enabling the acquisition of at least one physical measurement quantity based on atom interferometric acceleration measurement with reduced effort.

[0005] This task is solved by a quantum inertial measurement unit for detecting at least one physical quantity based on atom interferometric acceleration measurement, comprising: a) at least one atom trap configured to capture an atom cloud, b) at least one controllable partitioning device configured to generate, depending on at least one control signal, several spatially separated macroscopic sub-atom clouds in the atom cloud captured in the atom trap using cold or ultracold quantum gases, such as Bose-Einstein condensates, in a defined geometric arrangement, c) at least one atom-optical light field device configured to perform an atom-interferometric one-dimensional acceleration measurement using each of the generated macroscopic sub-atom clouds, wherein an acceleration value is determined for each macroscopic sub-atom cloud, d) at least one evaluation device configured toto determine a different physical quantity from the multiple one-dimensional acceleration values ​​obtained using at least one atom-optical light field device than the measured one-dimensional acceleration values.

[0006] The invention has the advantage that, with components of the device that are already required for one-dimensional acceleration measurement, several individual atom interferometers can be formed in the same atom trap with only a slight increase in the instrumental effort. This is achieved by means of spatially separated macroscopic partial atom clouds, each of which can be used individually for an atom interferometric one-dimensional acceleration measurement. In this way, several one-dimensional acceleration values ​​can be obtained with minimal instrumental effort, from which the desired other physical quantity can then be determined. The macroscopic partial atom clouds can be, for example, macroscopic quantum objects or other macroscopically separated atom clouds, such as thermal atom clouds at a few microkelvin or more, where no quantum character is directly apparent.

[0007] The atom optics light field device can, for example, resemble a laser interferometer, wherein the atom optics light field device can, for example, have a single- or multi-photon light field that incorporates the atom optics, for example in the form of beam splitting with momentum transfer.

[0008] According to an advantageous embodiment of the invention, the controllable partitioning device is configured to generate the macroscopic partial atom clouds in a defined geometric arrangement in the form of a regular or irregular two- or three-dimensional matrix arrangement. Such a defined geometric arrangement allows the equations for determining the other physical quantity from the multiple one-dimensional acceleration values ​​of the multiple atom interferometers or the macroscopic partial atom clouds to be simplified, thus minimizing the associated computational effort and, in particular, facilitating characterization / calibration through controlled adjustment of the distances.

[0009] According to an advantageous embodiment of the invention, the matrix arrangement comprises at least two, at least four, at least six, or at least nine matrix elements in the form of macroscopic partial atom clouds. In this way, a multitude of individual one-dimensional acceleration values ​​can be determined with a substantially consistent device setup, which in turn enables the determination of several different other physical quantities from these acceleration values. For example, the matrix arrangement can be configured as at least a 1x2 matrix or a 2x1 matrix. As will be shown below, a configuration as a 3x3 matrix is ​​advantageous, for instance.

[0010] According to an advantageous embodiment of the invention, the defined geometric arrangement of the macroscopic subatom clouds in a plane comprises an area of ​​at least 0.5 mm² or at least 1 mm². This ensures sufficient spatial separation of the individual macroscopic subatom clouds and, consequently, the ability to perform separate interferometric measurements on them. The macroscopic subatom clouds can be arranged in a single plane. Alternatively, they can be distributed over a three-dimensional space, for example, in the form of a three-dimensional matrix arrangement. Finally, they can also be distributed in a one-dimensional arrangement.

[0011] Generally speaking, the distance between the centers of adjacent macroscopic sub-atom clouds can be at least 0.3 mm, at least 0.7 mm, or at least 1 mm. In a three-dimensional matrix arrangement, the defined geometric arrangement of the macroscopic sub-atom clouds can encompass a volume of at least 0.125 mm³ or at least 1 mm³.

[0012] According to an advantageous embodiment of the invention, the evaluation unit is configured to determine one or more rotational rates, one or more rotational accelerations, one or more acceleration gradients, one or more magnetic field components, and / or at least one other inertial measurement quantity as physical measurements. Accordingly, the quantum inertial measurement unit according to the invention can be used very universally and allows highly accurate determinations of further physical measurements from the one-dimensional acceleration measurements.

[0013] The invention is suitable for both freely moving atom clouds and optically guided atom clouds, e.g., for interferometry in a waveguide. The at least one atom trap can, for example, be configured to trap the atom cloud in a vacuum system, e.g., a vacuum chamber or a glass cell.

[0014] According to an advantageous embodiment of the invention, the quantum inertial measurement unit comprises at least one waveguide, wherein the atom trap is configured to capture the atom cloud within the waveguide. This further simplifies the design of the device and increases the measurement accuracy. The macroscopic partial atom clouds can then be generated within the waveguide.

[0015] According to an advantageous embodiment of the invention, the atom optic light field device is configured to perform interferometric measurements on the macroscopic sub-atom clouds using coherent single- or multi-photon processes. This allows the functionalization of several macroscopic sub-atom clouds in the quantum inertial measurement unit as separate interferometers with low complexity and high measurement accuracy. The atom optic light field device can, for example, be configured to perform interferometric measurements on the macroscopic sub-atom clouds using at least one diffraction process, such as Bragg, double Bragg, Raman, double Raman, or single-photon diffraction.

[0016] According to an advantageous embodiment of the invention, the atom trap is designed as a magneto-optical atom trap. This allows for reliable provision of the atom cloud with minimal equipment requirements.

[0017] According to an advantageous embodiment of the invention, the quantum inertial measurement unit has a cooling device for cooling the atomic cloud, which includes an evaporative cooling arrangement. In this way, the atoms of the atomic cloud, cooled by laser irradiation, can be cooled further into the range of cold or ultracold quantum gases. The evaporative cooling arrangement is configured to perform evaporative cooling of the atomic cloud. During evaporative cooling, the most energetic atoms are removed from the atomic cloud, for example, by radio frequency transitions between the different Zeeman states in a magnetic trap.

[0018] According to an advantageous embodiment of the invention, the controllable partitioning device comprises at least one optical dipole trap and / or at least one magnetic trap. The controllable partitioning device serves to divide the atomic cloud into separate macroscopic sub-clouds. This is achieved particularly efficiently with minimal equipment by means of an optical dipole trap and / or at least one magnetic trap.

[0019] According to an advantageous embodiment of the invention, the at least one optical dipole trap has at least two beam paths, in particular at least two intersecting beam paths or at least two parallel beam paths. In this way, atom interferometric measurements can be performed on a macroscopic partial atom cloud located in the region of the intersection point of the beams in the area of ​​the intersecting beams. In the case of parallel beams, the measurements can be performed one-dimensionally on two macroscopic partial atom clouds in the beam path.

[0020] According to an advantageous embodiment of the invention, the controllable splitting device comprises at least one controllable optical splitting unit, in particular a deflector, by which at least one beam path of the optical dipole trap can be split into several partial beam paths. This makes it possible to perform several separate atom interferometric measurements on the separated macroscopic partial atom clouds with only a slight increase in the instrumental complexity compared to an atom interferometer set up for one-dimensional acceleration measurement. The controllable optical deflector can, for example, be an acousto-optic deflector set up to generate different light beam deflections depending on applied alternating signals with varying frequencies.

[0021] The aforementioned problem is also solved by a method for detecting at least one physical quantity based on atom interferometric acceleration measurement using a quantum inertial measurement unit, in particular a quantum inertial measurement unit of the type described above, with the following features: a) An atom cloud is trapped by means of an atom trap, b) depending on at least one control signal, several spatially separated macroscopic sub-atom clouds are generated in the atom cloud trapped in the atom trap by means of a controllable partitioning device using cold or ultracold quantum gases, such as Bose-Einstein condensates, in a defined geometric arrangement, c) an atom interferometric one-dimensional acceleration measurement is carried out using each of the generated macroscopic sub-atom clouds by means of an atom optic light field device, whereby an acceleration value is determined for each macroscopic sub-atom cloud, d) a different physical quantity is determined from the several one-dimensional acceleration values ​​obtained by means of the at least one atom optic light field device by means of an evaluation device than the measured one-dimensional acceleration values.

[0022] This also allows the previously explained advantages to be realized.

[0023] The invention described here is suitable for the field of inertial sensing and navigation. In particular, a method is described with which a conventional atom interferometric 1D acceleration measurement with cold atoms can be extended to multiple spatial directions and additional measured quantities, in particular angular velocity, angular acceleration, spatial gradients, curvature and higher orders, using dynamic optical potentials.

[0024] The invention solves the problem described at the outset and thus provides a simple way – without significantly affecting the complexity and size of the system – to considerably expand the functionality of existing systems with minimal effort. Such an expansion is naturally of particular importance where SWaP budgets ( Size , Weight , and power) is expensive and important, i.e., on transportable platforms, for example, on satellite missions for Earth observation or in inertial navigation using hybrid sensors. Therefore, important applications of the invention arise in the field of inertial navigation and sensing, where such a setup on mobile platforms is used to evaluate local gravity, accelerations, and their spatial derivatives and rotations. The large number of individual, correlable measurements in the invention provides a disruptive advantage over the prior art through the possibility of differential noise suppression (e.g., vibration noise) and system characterization (e.g., wavefront analysis of the beam splitter light field using moving, scalable atomic arrays and modeling).The additional inertial measurements can therefore play a central role in the characterization and control of systematic effects, extending beyond the application scenario itself.

[0025] The sensitivity to rotations is based on the combination of two acceleration or velocity measurements separated by a baseline, as is common, for example, for inertially stabilized platforms [9] or as proposed in Ref.

[10] for the combination of atom interferometers. The invention benefits from continuous scalability (distances). dx and dy (These axes can be freely varied from 0 mm to several millimeters), which can be used to adjust the measurement sensitivity to ambient noise or target observables, as well as to characterize or calibrate the measurement. Further sensitive axes are conceivable through the use of 3D interferometer configurations.

[0026] The invention is explained in more detail below with reference to exemplary embodiments and drawings.

[0027] They show Figure 1: A schematic representation of the quantum inertial measurement unit; Figure 2: The arrangement of several macroscopic sub-atom clouds that can be generated in the quantum inertial measurement unit; Figure 3: Transport trajectories of the macroscopic sub-atom clouds; Figure 4: Transport efficiency of the sub-atom clouds for different ramp durations; Figure 5: Beam splitter efficiency as a function of pulse duration and free-fall time; Figure 6: Beam splitter efficiency as a function of Y-position and incident time; Figure 7: Output signals of the nine simultaneous atom interferometers; Figure 8: Output signals of the nine simultaneous atom interferometers in parametric representation; Figure 9: Output signals of the nine simultaneous atom interferometers in the 1D waveguide.

[0028] The Figure 1Figure 1 shows a highly schematic representation of a quantum inertial measurement unit for measuring a physical quantity based on atom interferometric acceleration measurement. The quantum inertial measurement unit comprises an atom trap 1, 3, 13, 16. The atom trap also includes optical dipole traps 11, 12, lens systems 6, 7, as well as delay plates 9 and beam splitters 10. For example, 2D acousto-optic deflectors (AOD) 2 can be used as a controllable splitting device. BEC collimators 4 and dichroic mirrors 8 are provided as the atom-optical light field device for separating the atom-optical light field and dipole trap beams. An evaluation device 17, such as a computer, is provided for data analysis.

[0029] The quantum inertial measurement unit can, for example, have the following individual components: 1. A first laser, e.g., a laser for generating time-averaged optical potentials (e.g., a 55 W 1064 nm laser), is used to trap the atom cloud pre-cooled in the magnetic trap. Subsequent evaporative cooling of the atom ensembles leads to the generation of quantum-degenerate gases. 2. 2D acousto-optic deflectors (AODs): The light from the first laser is refracted by the acousto-optic deflectors, and the first diffraction order is split into several partial beams by a suitable applied RF signal. These partial beams are freely adjustable in position (within the range of a few millimeters) and amplitude. By using two 2D AODs, a 2D grating of potential minima can be generated in experimental chamber 3. 3. Experimental chamber with ultra-high vacuum (UHV). 4. Bragg collimator: The two partial beams used for atom interferometry are guided to the Bragg collimator via a fiber optic cable.This system sends collimated interferometric beams with a diameter of, for example, 6.5 mm through the experimental chamber 3, where they are retroreflected by reflectors 15. The polarizations of the partial beams are then rotated by 90° by a λ / 4 delay plate 14. This makes the atomic ensembles usable for interferometric measurements. Five macroscopic partial atom clouds, such as Bose-Einstein condensates (BECs), are arranged in the array. The lattice-like arrangement of potential minima makes it possible to generate a single BEC in each. The BECs are separated from each other by distances dx and dy. These distances can be chosen and changed as desired. 6 beam telescopes for widening the beam of the first laser 1. 7 Focusing lenses: These lenses focus the dipole trap beam in the center of the experimental chamber 3. 8 Dichroic mirror, which is transparent to the dipole trap beam (1064 nm) and reflective to the interferometry beams (780 nm).9. λ / 2 delay plates to adjust the polarization of the dipole trap beam. The refractive efficiency of the AODs is strongly dependent on the polarization of the light. At the center of experimental chamber 3, both dipole trap beams must be orthogonally polarized to avoid interference effects. 10. Polarization-dependent beam splitter (PBS) to split the dipole trap beam into two beams that create a crossed dipole trap at the center of the experimental chamber. 11. ODT modes BP1: Optical modes of the dipole trap beam in the x-direction. The modes are generated by the 2D AOD (2). 12. ODT modes BP2: Optical modes of the dipole trap beam in the y-direction. The modes are generated by the 2D AOD (2). 13. MOT collimators that provide laser light for the initial cooling stages before loading the optical dipole trap.Furthermore, there is a pair of collimators in the z-direction above and below the center of the experimental chamber, as well as a pair of Hemholtz coils above and below the experimental chamber (not shown) to provide the necessary magnetic fields. 14 Polarization filter (λ / 4 delay plate) 15 Reflector 18 For safety reasons, the dipole trap beams are blocked behind the experimental chamber by beam traps.

[0030] In a region 16, several mutually separated macroscopic sub-atom clouds 5 are then generated in a matrix arrangement, shown here in a 3x3 matrix, i.e., nine macroscopic sub-atom clouds 5, with which the in Figure 2The nine independent interferometers I1, I2, I3, I4, I5, I6, I7, I8, and I9 shown can be used to generate the light. For this purpose, the light from the first laser 1 is split into two beam paths in the polarization-dependent beam splitter 10, which are guided diagonally through the experimental chamber 3. In each beam path, the respective beam is split by the controllable splitting device into, for example, three adjacent partial beams.

[0031] As an embodiment, a 2D arrangement of Bose-Einstein condensates (BEC) 5 is described, which lies in a cross-sectional plane of the two optical dipole trap beams 11, 12. Due to the large spatial displacement (approximately a few millimeters) of the foci of the two dipole beams 11, 12, it is possible to generate several potential wells in two dimensions simultaneously and to load them with 87< Rb atoms previously trapped and cooled in a magnetic trap. A BEC 5 can be generated in each of these potential wells by evaporative cooling. The number of ultracold atoms in the arrangement is approximately 3 x 105. The following are described: Optical transport of the arrangement The distances between the BECs dx / y can be scaled to adjust the differential phase sensitivity for subsequent interferometric measurements. The maximum area enclosed by the setup is macroscopic and can be quantified as 1.5 mm² after transport. Light pulse atom interferometryThe beam splitter and mirror pulses of the interferometry sequence are demonstrated. Results of interferometric measurements are then presented. Phase sensitivity and discussion The differential phase sensitivity of the arrangement is specified, and further information is provided. proof-of-principle Experiments proposed. Optical transport of the arrangement

[0032] By applying suitable frequency ramps to the radio frequency signals applied to the acousto-optic deflectors (AOD) 2, the distance between the BECs 5 can be reduced from an initial 300 µm ( dx ) or 150 µm ( dy ) to a maximum of 750 µm ( dx ) or 500 µm ( dy ) will be increased (see below). Figure 3 The transport trajectories can be sigmoidal frequency ramps, with maximum transport efficiency for ramp durations of 600 ms. Peak transport efficiencies of approximately 95% have been measured. For longer ramp durations, characteristic exponential lifetime losses can be observed.

[0033] The Figure 3 This shows the transport trajectories of the individual BECs in the array. The measured trajectories of the BECs in the array are shown here. Each image describes the x- and y-position of a single BEC as a function of the transport time in milliseconds. The numbering is sequential from left to right, 1 to 9. The trajectories shown are examples of those resulting from a distance between the BECs of dx / y = 600 / 300 µm.

[0034] The Figure 4 This shows transport efficiencies for different ramp durations of 300, 400, 600, 800, and 1000 ms. The efficiency was determined by measuring the number of atoms before and after the ramp, and the mean values ​​for the ratio Teff = Nafter / Nbefore are plotted. Light pulse atom interferometry

[0035] The interferometric measurements on the BEC array are performed using the well-known technique of double Bragg diffraction. In this process, the BECs of the array are converted into the momentum states |±2 hk ) transferred (beam splitter) and after an evolutionary period T inverted (mirror). After a second evolutionary period T A new beam splitter pulse is injected, closing the interferometer. The ratio of the measured populations of the pulse states |2 hk The values ​​) and |0) allow conclusions to be drawn about the phase Φ of the interferometer. The beam splitter and mirror pulses are realized by two orthogonally polarized, retroreflected light fields. The laser system used for this is in Figure 1The laser beams, after exiting the fiber and passing through the telescope, have a Gaussian profile and a diameter of approximately 0.65 cm. The power in the beams is about 12 mW. Before the double Bragg pulses are injected, the dipole trap is switched off, and the atomic ensembles are in free fall. Since the interferometry beams are oriented almost horizontally, the time between switching off the dipole trap and the last beam splitter pulse must be limited to a maximum of 20 ms to ensure sufficient spatial overlap between the Bragg beams and the falling trajectory of the atoms. Rabi oscillations for three occurrence times are shown. t 1 = 5 ms, t 2 = 9 ms and tFigure 3 shows the 15 ms prior to the application of the Bragg laser pulses. The intensity profile of the Bragg pulses is approximately Gaussian, which results in a slowing of the Rabi oscillation for longer occurrence times, as the atoms fall out of the center of the interferometry beams and the Rabi frequency decreases with the square root of the intensity. The maximum efficiency of the beam splitter can be estimated at ~95%. t 1 and ~85% for t 3. By shifting the arrangement orthogonal to the interferometric beams (along the y-axis), their intensity profile can be measured. For this purpose, measurements were taken for two different yThe positions of the arrangement were determined. In the first measurement, the positions of the columns, referenced to the camera chip of the absorption image, can be specified as 830, 1230, and 1630 microm, and in the second as 680, 1080, and 1480 microm. The mirror pulse has a maximum efficiency of approximately 85% with roughly the same pulse duration as in section 4 and a time interval of 5 ms. This is achieved by doubling the radio frequency power at the switching AOM (last AOM in the Bragg laser system).

[0036] The Figure 5 This shows the beam splitter efficiency as a function of pulse duration and free-fall time (legend). Rabi oscillations are visible, scanned by sequentially increasing the pulse duration τ from 112 to 472 µs. The times t1 = 5 ms, t2 = 9 ms, t3 = 15 ms represent the duration of the atoms' free fall before the application of the Bragg laser pulses.

[0037] The Figure 6This graph shows the beam splitter efficiency as a function of the y-position and incidence time. The graph depicts the beam splitter efficiencies for a pulse duration τ of 276 µs and varying incidence times. The y-positions of the columns in the array are given in the top row. The efficiency increases from smaller to larger y-positions, indicating that the center of the interferometric beams is shifted in the y-direction.

[0038] First, the initial phase of the interferometer scales with the scale factor Φ = k eff a- eff T 2< with the effective wave vector of double Bragg diffraction k eff and the effective acceleration a eff , which is induced by the tilting of the interferometry beams (angle α in Figure 3 The acceleration is given by a eff = g • sin(α), where g = 9.81 m / s² is the acceleration due to gravity. The output signals of all 9 simultaneous interferometers with d x / y = 600 / 300 µm are in Figure 8 depicted.

[0039] The Figure 7 shows the output signals of the 9 simultaneous atom interferometers as a function of T The output signals of the nine atom interferometers, implemented with the BECs of the 2D array, are shown. (Using the fit function...) P i T = a i + b i × cos a i , eff k eff T 2 + d × exp − Tf The effective acceleration can be determined. The offset AI , contrast bi , frequency ai,eff , Offset phase d and decrease in contrast f The fit parameters are denoted by i, which represents the i-th interferometer. This is significant for inertial sensors. ai,eff , which can be determined for interferometers 1–9 as 0.0747 ± 0.0007, 0.0771 ± 0.00064, 0.0771 ± 0.0004, 0.0750 ± 0.0006, 0.0775 ± 0.0006, 0.0768 ± 0.0004, 0.0752 ± 0.0005, 0.0770 ± 0.0005, 0.0765 ± 0.0005 in m / s². The correlation of the measurement data is shown in Figure 8.

[0040] The Figure 8The output signals of the 9 simultaneous atom interferometers are shown in parametric form. To illustrate correlations, each interferometer signal is plotted against the average interferometer (5).

[0041] The Figure 9 shows the output signals of the 9 simultaneous atom interferometers in the 1D waveguide, or output signals of the nine atom interferometers when the atoms are held in the 1D waveguide. Phase sensitivity and discussion

[0042] Each BEC 5 of this arrangement can be used for interferometric measurements via double Bragg diffraction. In the Figure 2 In the illustrated embodiment, this results in a 3x3 matrix of interferometers I1, I2, I3, I4, I5, I6, I7, I8, I9. The correlated measurements obtained in this way can be read out differentially to obtain information about acting i) accelerations, ii) gradients, iii) rotations and iv) rotational accelerations.

[0043] The sensitivity to accelerations in the x-direction along the Bragg beams is intrinsic to each of the 9 interferometers. This can be determined by correlating neighboring interferometers in x -Direction (series) allows conclusions to be drawn about gradients, each with integer multiples of the distance. dx , scale. Rotation rates and accelerations can initially be determined by a rotational movement of the retroreflective mirror of the Bragg beam positioned at a distance. x M to the atoms with coordinates x →< M = ( x M , 0,0). The phase of the individual output signals of the interferometers is given by: ϕ i = 2 k eff T 2 a eff + v yi 2 Ω z + Ω M + Ω ˙ M T + 2 v zi Ω y + yi Ω x Ω y + Ω ˙ M − x i Ω y 2 + Ω z 2 + z i Ω z Ω x + 2 x i − x M Ω M 2

[0044] where Ω x / y / z is a rotation rate about the corresponding axis, (x / y / z) i is the position and v(x / y / z) i are the velocities of the individual BEC before the application of the Bragg rays, xM is the distance between the retroreflective mirror and its center of rotation, and Ω M , Ω M The rotation rate, or rather its rotation rate acceleration, is described. Differential phases between the individual interferometers scale with the distance between the BECs of the arrangement; for the largest possible differential phase ΔΦij = Φi - Φj, the distance must be... d x / y The interaction between the BECs of the array is maximized. By implementing an amplified piezo actuator that can tilt the mirror, the mirror's rotation rate can be adjusted and rotations simulated. Similarly, a phase difference can be generated and gradually changed in a controlled manner.

[0045] Due to the limited interferometry duration, T in the first proof-of-principleExperiments only last a few milliseconds. To demonstrate rotation measurements with the mirror, the rotation rates or accelerations Ω must be determined. M , Ω M >0.1 rad / s or rad / s²<, which is possible with the piezo actuator. An increase in the evolution time can be achieved with guided interferometry; for this, the dipole trap beam is switched off in the y-direction. As a result, the atoms in the interferometry beam direction are no longer trapped and can be held in the resulting 1D waveguide and manipulated with the interferometry beams. Initial interferometry results with the arrangement in the waveguide are shown in Figure 7, but are not yet fully understood. a eff Scale factors from the in Figure 7The measurements shown increase column by column: They are smallest for interferometers 1, 4, and 7 and increase successively column by column for interferometers 2, 5, and 8, and for 3, 6, and 9. Tilting of the interferometer beams should be represented by the same scale factors. a eff to understand the observed deviation, 3D simulations of the interferometer sequences are performed in collaboration with Naceur Gaaloul's group.

[0046] By imposing an initial velocity orthogonal to the interferometry beams, the v yiThe dependent term of equation 2 was measured. Using a 2 x 3 array, semi-sigmoidal frequency ramps, serving as the input signal of the AOD in BP1, were measured. The BEC array was accelerated column by column using these ramps, and velocities of 70 mm / s for BEC 3, 6 (right column) and 35 mm / s for BEC 2, 5 (middle column) were recorded for a ramp with a maximum frequency deviation of 6 MHz (right column) and 3 MHz (middle column) and a ramp duration of 65 ms. The left column was held stationary. References

[0047] [1] J. M. McGuirk et al. "Sensitive absolute-gravity gradiometry using atom interferometry". In: Physical Review A 65.3 (Feb. 2002). Publisher: American Physical Society (APS). DOI: 10.1103 / physreva.65.033608. [2] G. Rosi et al. "Measurement of the Gravity-Field Curvature by Atom Interferometry". In: Physical Review Letters 114.1 (Jan. 2015). Publisher: American Physical Society, p. 013001. DOI: 10.1103 / PhysRevLett.114.013001. URL: https: / / link.aps.org / doi / 10.1103 / PhysRevLett.114.013001 (visited on 01 / 02 / 2023). [3] Romain Gautier et al. "Accurate measurement of the Sagnac effect for matter waves". en. In: Science Advances 8.23 (Dune 2022), eabn8009. ISSN: 2375-2548. DOI: 1 0.1126 / sciadv.abn8009. https: / / www.science.org / doi / 10.1126 / sci-adv.abn8009 (visited on 01 / 02 / 2023). [4] P. Berg et al. "Composite-Light-Pulse Technique for High-Precision Atom Inter-ferometry". In: Phys. Rev. Lett. 114.6 (Feb. 2015). Publisher: American Physical Society, p. 063002. DOI: 10.1103 / PhysRevLett.114.063002. [5] J. K. Stockton, K. Takase, and M. A. Kasevich. "Absolute Geodetic Rotation Measurement Using Atom Interferometry". In: Physical Review Letters 107.13 (Sept. 2011). Publisher: American Physical Society, p. 133001. DOI: 10.1103 / PhysRevLett.107.133001. URL: https: / / link.aps.org / doi / 10.1103 / PhysRevLett.107.133001 (visited on 01 / 05 / 2023). [6] B. Barrett et al. "Multidimensional Atom Optics and Interferometry". In: Phys. Rev. Lett. 122.4 (Feb. 2019). Publisher: American Physical Society, p. 043604. DOI: 10. 1103 / PhysRevLett.122.043604. URL: https: / / link.aps.org / doi / 10.1103 / PhysRev-Lett.122.043604. [7] Matthias Gersemann et al. "Differential interferometry using a Bose-Einstein condensate". In: The European Physical Journal D 74.10 (2020), p. 203. ISSN: 1434-6079. DOI: 10.1140 / epjd / e2020-10417-8. URL: https: / / doi.org / 10.1140 / epjd / e2020-10417-8. [8] Susannah M. Dickerson et al. "Multiaxis Inertial Sensing with Long-Time Point Source Atom Interferometry".In: Physical Review Letters 111.8 (Aug. 2013). Publisher: American Physical Society, p. 083001. DOI: 10 1103 / PhysRevLett 111. 083001. URL: https: / / link.aps.org / doi / 10.1103 / PhysRevLett.111.083001 (visited on 01 / 03 / 2023). [9] A. Wanner et al. "Seismic attenuation system for the AEI 10 meter Prototype". en. In: Classical and Quantum Gravity 29.24 (Nov. 2012). Publisher: IOP Publishing, p. 245007. ISSN: 0264-9381. DOI: 10.1088 / 0264-9381 / 29 / 24 / 245007. URL: https: / / dx doi.org / 10.1088 / 0264-9381 / 29 / 24 / 245007 (visited on 07 / 05 / 2023).

[10] Nathan Shettel and Rainer Dumke. Emulating an Atomic Gyroscope with Multiple Accelerometers. arXiv:2301.11155 [physics]. Jan. 2023. DOI: 10.48550 / arXiv.2301.11155. URL: http: / / arxiv.org / abs / 2301.11155 (visited on 01 / 31 / 2023).

Claims

1. Quantum inertial measurement unit for detecting at least one physical measurement quantity based on atom-interferometric acceleration measurement, comprising: a) at least one atom trap (1, 3, 11, 12, 13, 16) configured to capture an atomic cloud, b) at least one controllable splitting device (2) configured, depending on at least one control signal, to generate within the atomic cloud trapped in the atom trap (1, 3, 11, 12, 13, 16) a plurality of spatially separated macroscopic partial atomic clouds (5) composed of cold or ultracold quantum gases, such as Bose-Einstein condensates, in a defined geometric arrangement, c) at least one atom-optical light-field device (4, 6, 7, 8, 9, 10) configured to perform, by means of the generated macroscopic partial atomic clouds (5), an atom-interferometric one-dimensional acceleration measurement for each of the macroscopic partial atomic clouds (5), wherein an acceleration value is determined for each macroscopic partial atomic cloud (5), d) at least one evaluation device (17) configured to determine, from the plurality of one-dimensional acceleration values obtained by means of the at least one atom-optical light-field device (4, 6, 7, 8, 9, 10), a physical measurement quantity other than the measured one-dimensional acceleration values.

2. Quantum inertial measurement unit according to claim 1, characterized in that the controllable splitting device (2) is configured to generate the macroscopic partial atomic clouds (5) in a defined geometric arrangement in the form of a regular or irregular two- or three-dimensional matrix arrangement.

3. Quantum inertial measurement unit according to claim 2, characterized in that the matrix arrangement comprises at least two, at least four, at least six, or at least nine matrix elements, each in the form of a macroscopic partial atomic cloud (5).

4. Quantum inertial measurement unit according to any one of the preceding claims, characterized in that the defined geometric arrangement of the macroscopic partial atomic clouds (5) in a plane covers an area of at least 0.5 mm2 or at least 1 mm2.

5. Quantum inertial measurement unit according to any one of the preceding claims, characterized in that the evaluation device (17) is configured to determine, as the physical measurement quantity, one or more rotation rates, one or more angular accelerations, one or more acceleration gradients, one or more magnetic field components, and / or at least one other inertial measurement quantity.

6. Quantum inertial measurement unit according to any one of the preceding claims, characterized in that the quantum inertial measurement unit comprises at least one waveguide, the atom trap (1, 3, 11, 12, 13, 16) being configured to capture the atomic cloud within the waveguide.

7. Quantum inertial measurement unit according to any one of the preceding claims, characterized in that the atom-optical light-field device (4, 6, 7, 8, 9, 10) is configured to perform interferometric measurements on the macroscopic partial atomic clouds (5) by means of coherent single- or multi-photon processes.

8. Quantum inertial measurement unit according to any one of the preceding claims, characterized in that the atom trap (1, 3, 11, 12, 13, 16) is designed as a magneto-optical atom trap.

9. Quantum inertial measurement unit according to any one of the preceding claims, characterized in that the quantum inertial measurement unit comprises a cooling device (13) for cooling the atomic cloud, said cooling device comprising an evaporative cooling arrangement.

10. Quantum inertial measurement unit according to any one of the preceding claims, characterized in that the controllable splitting device (2) comprises at least one optical dipole trap and / or at least one magnetic trap.

11. Quantum inertial measurement unit according to claim 10, characterized in that the at least one optical dipole trap comprises at least two beam paths, in particular at least two intersecting beam paths or at least two parallel beam paths.

12. Quantum inertial measurement unit according to any one of the preceding claims, characterized in that the controllable splitting device (2) comprises at least one controllable optical splitting unit, in particular a deflector, by means of which at least one beam path of the optical dipole trap can be split into a plurality of partial beam paths.

13. Method for detecting at least one physical measurement quantity based on atom-interferometric acceleration measurement using a quantum inertial measurement unit, in particular a quantum inertial measurement unit according to any one of the preceding claims, comprising the following steps: a) capturing an atomic cloud by means of an atom trap (1, 3, 11, 12, 13, 16), b) generating, depending on at least one control signal, within the atomic cloud trapped in the atom trap, a plurality of spatially separated macroscopic partial atomic clouds (5) composed of cold or ultracold quantum gases, such as Bose-Einstein condensates, in a defined geometric arrangement by means of a controllable splitting device (2), c) performing, by means of an atom-optical light-field device (4, 6, 7, 8, 9, 10), for each of the generated macroscopic partial atomic clouds (5), an atom-interferometric one-dimensional acceleration measurement, wherein an acceleration value is determined for each macroscopic partial atomic cloud (5), d) determining, by means of at least one evaluation device (17), from the plurality of one-dimensional acceleration values obtained by the at least one atom-optical light-field device (4, 6, 7, 8, 9, 10), a physical measurement quantity other than the measured one-dimensional acceleration values.

14. Method according to claim 13, characterized in that one or more rotation rates, one or more angular accelerations, one or more acceleration gradients, one or more magnetic field components, and / or at least one other inertial measurement quantity is determined as the physical measurement quantity.