Simultaneous dual-species matter-wave accelerometer

Abstract

We report the realization of a matter-wave interferometer based on Raman transitions which simultaneously interrogates two different atomic species ( 87 Rb and 85 Rb). The simultaneous aspect of our experiment presents encouraging preliminary results for future dual-species atom interferometry projects and seems very promising by taking advantage of a differential acceleration measurement. Indeed the resolution of our differential accelerometer remains lower than 3.9 × 10 −8 g even with vibration levels up to 1 × 10 −3 g thanks to common-mode vibration noise rejection . An atom based test of the Weak Equivalence Principle has also been carried out leading to a differential free fall measurement between both isotopes of ∆g/g = (1.2 ± 3.2) × 10 −7 .Light pulse atom interferometers [1, 2] have proven to be very high performance sensors with the development in the last decades of cold atom gravimeters [3], gravity gradiometers [4] and gyroscopes [5]. In addition to the undeniable contribution they could bring in practical applications such as inertial navigation and geophysics, they appear very promising for exploring fundamental physics such as for the determination of the fine structure constant [6], the gravitationnal constant [7,8], but also for testing the Einstein's theory of general relativity with quantum objects [9]. In that field, atom interferometers seem notably promising for detecting gravitational waves [10], exploring short range forces [11,12] and testing the Weak Equivalence Principle (WEP) [13].In the context of testing the WEP, some projects under development aim to measure the acceleration of two different atomic species during few seconds of free fall in order to achieve highly sensitive measurements as it can be obtained in 10 m tall atomic fountains [9], drop towers [14], sounding rockets, parabolic flights [15] and satellites [16]. To date, a single atom based ground test of the WEP was carried out by alternatively handling both isotopes of rubidium [13]. This method, providing a non simultaneous differential measurement, exhibit a sensitivity limited by vibration noise, such as state of the art gravimeters [17,18]. A special interest must thus be paid to develop atom interferometers which will simultaneously interrogate two different atomic species in order to take full advantages of a differential measurement and to achieve the targeted sensitivity and accuracy.

Characterization of a simultaneous dual-species atom interferometer for a quantum test of the weak equivalence principle

“…In our experiment, the main systematics are the impact of additional laser lines, the two-photon light shift, the Coriolis effect and wave-front aberrations of the Raman laser [23].…”

“…To avoid this effect in quantum based test of the WEP, a special attention must be paid to the simultaneous interrogation of both quantum proof bodies in order to benefit from an efficient common-mode noise rejection allowed by the differential measurement [23].…”

“…Many experiments and projects worldwide, also prove that quantum sensors appear to be very promising tools for exploring many aspects of fundamental physics as the determination of the fine-structure constant α [16] and the Newtonian gravity constant G [17,18], the detection of gravitational waves [19], the exploration of shortrange forces [20,21] and quantum based tests of the Weak Equivalence Principle (WEP) [22][23][24][25][26].…”

Species-selective confinement of atoms dressed with multiple radiofrequencies

“…This combination of species requires a comparatively simple laser scheme; the required cooling and repumping transitions lie within a span of 6.6 GHz, accessible to a single-frequency laser source via electro-optic modulation of the carrier [42,43] or the modulation of current in an injection locked laser diode [44]. Species-selective manipulations of these isotopes using dipole traps are difficult because of the similarity of their optical transition frequencies, but their dissimilar |g F | values makes them well suited to the above method.…”

Recoil-Sensitive Lithium Interferometer without a Subrecoil Sample

“…They are used for inertial sensing [2,3], gravity gradiometry [4] and tests of fundamental physics [5][6][7][8][9][10][11][12][13][14][15]. Ramsey-Bordé interferometers, in particular, measure the mass m of an atom through the kinetic energy ω r = 2 k 2 /(2m) it gains after recoiling from the interaction with a photon ( is the reduced Planck constant).…”