Quantum theory of atomic clocks and gravito-inertial sensors: an update

“…The geometry of the device is fully determine by the interaction between the initial atomic beam and the lasers ; moreover the geometrical description is already an idealized model ; Therefore a full treatment of the atom-laser interaction in a gravitational field is obviously necessary to study the response of the ASU (see [9]). However the geometrical model is useful to give a physical intuition of the phenomena.…”

Section: A Shift : O S and O ′mentioning

confidence: 99%

Gravitational Perturbations on Local Experiments in a Satellite: The Dragging of Inertial Frame in the HYPER Project

Angonin¹,

Ovido²,

Tourrenc³

2004

General Relativity and Gravitation

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We consider a nearly free falling Earth satellite where atomic wave interferometers are tied to a telescope pointing towards a faraway star. They measure the acceleration and the rotation relatively to the local inertial frame.We calculate the rotation of the telescope due to the aberrations and the deflection of the light in the gravitational field of the Earth. We show that the deflection due to the quadrupolar momentum of the gravity is not negligible if one wants to observe the Lense-Thirring effect of the Earth.We consider some perturbation to the ideal device and we discuss the orders of magnitude of the phase shifts due to the residual tidal gravitational field in the satellite and we exhibit the terms which must be taken into account to calculate and interpret the full signal.Within the framework of a geometric model, we calculate the various periodic components of the signal which must be analyzed to detect the Lense-Tirring effect. We discuss the results which support a reasonable optimism.As a conclusion we put forward the necessity of a more complete, realistic and powerful model in order to obtain a final conclusion on the theoretical feasibility of the experiment as far as the observation of the Lense-Thirring effect is involved.

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“…The Raman lasers are copropagating so that a nearly zero momentum is transfered during the Raman transition. In this configuration, the two successive π 2 pulses enable to record optically induced Ramsey fringes that are the signature of the matter waves interferences between the two interferometer paths [24,25]. After the Raman pulses, the MOT beams are switched on at resonance and a photodiode monitors the fluorescence which is proportional to the number of atoms.…”

mentioning

confidence: 99%

Light-pulse atom interferometry in microgravity

et al. 2009

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Abstract. We describe the operation of a light pulse interferometer using cold 87 Rb atoms in reduced gravity. Using a series of two Raman transitions induced by light pulses, we have obtained Ramsey fringes in the low gravity environment achieved during parabolic flights. With our compact apparatus, we have operated in a regime which is not accessible on ground. In the much lower gravity environment and lower vibration level of a satellite, our cold atom interferometer could measure accelerations with a sensitivity orders of magnitude better than the best ground based accelerometers and close to proven spaced-based ones. PACS. PACS-key discribing text of that key -PACS-key discribing text of that keyAtom interferometry is one of the most promising candidates for ultra-accurate measurements of gravito-inertial forces [1], with both fundamental [2,3,4,5] and practical (navigation or geodesy) applications. Atom interferometry is most often performed by applying successive coherent beam-splitting and -recombining processes separated by an interrogation time T to a set of particles [6]. Understanding matter waves interferences phenomena follows from the analogy with optical interferometry [7,8]: the incoming wave is separated into two wavepackets by a first beam-splitter; each wave then propagates during a time T along a different path and accumulates a different phase; the two wavepackets are finally recombined by a last beam-splitter. To observe the interferences, one measures the two output-channels complementary probability amplitudes which are sine functions of the accumulated phase difference ∆φ. This phase difference increases with the paths length, i.e. with the time T between the beamsplitting pulses.When used as inertial sensors [9,10], the atoms are usually left free to evolve during the interrogation time T so that the interferometer is only sensitive to gravitoinertial effects. In particular, one avoids residual trapping fields that would induce inhomogeneities or fluctuations and would affect the atomic signal. The interrogation time T is consequently limited by, on the one hand, the free expansion of the atomic cloud, and, on the other hand, the free fall of the atomic cloud. The limitation of expansion is alleviated by the use of ultracold gases [11,12], Send offprint requests to: Fig. 1. Top: The atom interferometer assembled in the Airbus. The main rack on the left houses the laser sources and the control electronics. The rack on the front right contains the uninterruptable power-supply, the electrical panel and the high-power laser part. The rack on the back right hosts atomoptics part of the experiment. Bottom: the architecture of the atom interferometer.

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Quantum theory of atomic clocks and gravito-inertial sensors: an update

Cited by 76 publications

References 9 publications

Is it possible to detect gravitational waves with atom interferometers?

Is it possible to detect gravitational waves with atom interferometers?

Gravitational Perturbations on Local Experiments in a Satellite: The Dragging of Inertial Frame in the HYPER Project

Light-pulse atom interferometry in microgravity

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