Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Advances in atomic physics, such as cooling and trapping of atoms and molecules and developments in frequency metrology, have added orders of magnitude to the precision of atom-based clocks and sensors. Applications extend beyond atomic physics and this article reviews using these new techniques to address important challenges in physics and to look for variations in the fundamental constants, search for interactions beyond the standard model of particle physics, and test the principles of general relativity.

Search for New Physics with Atoms and Molecules

Quantum metrology uses quantum entanglement--correlations in the properties of microscopic systems--to improve the statistical precision of physical measurements. When measuring a signal, such as the phase shift of a light beam or an atomic state, a prominent limitation to achievable precision arises from the noise associated with the counting of uncorrelated probe particles. This noise, commonly referred to as shot noise or projection noise, gives rise to the standard quantum limit (SQL) to phase resolution. However, it can be mitigated down to the fundamental Heisenberg limit by entangling the probe particles. Despite considerable experimental progress in a variety of physical systems, a question that persists is whether these methods can achieve performance levels that compare favourably with optimized conventional (non-entangled) systems. Here we demonstrate an approach that achieves unprecedented levels of metrological improvement using half a million (87)Rb atoms in their 'clock' states. The ensemble is 20.1 ± 0.3 decibels (100-fold) spin-squeezed via an optical-cavity-based measurement. We directly resolve small microwave-induced rotations 18.5 ± 0.3 decibels (70-fold) beyond the SQL. The single-shot phase resolution of 147 microradians achieved by the apparatus is better than that achieved by the best engineered cold atom sensors despite lower atom numbers. We infer entanglement of more than 680 ± 35 particles in the atomic ensemble. Applications include atomic clocks, inertial sensors, and fundamental physics experiments such as tests of general relativity or searches for electron electric dipole moment. To this end, we demonstrate an atomic clock measurement with a quantum enhancement of 10.5 ± 0.3 decibels (11-fold), limited by the phase noise of our microwave source.

Measurement noise 100 times lower than the quantum-projection limit using entangled atoms

Matter-wave interferometers provide an opportunity to measure whether quantum superpositions exist at macroscopic length scales or only at microscopically small scales; now such instruments have demonstrated quantum interference of wave packets separated by 54 cm. Matter-wave interferometers, which allow for the observation of interference pattern of atomic wave packets that are split and recombined, have proven to be useful tools in precision metrology and fundamental research. These interferometers provide an opportunity to measure whether quantum superpositions exist at macroscopic length scales or only at microscopically small scales. But a truly macroscopic scale that would be necessary for such a test had not been reached in matter-wave interferometers to date. Here the authors show quantum interference of wave packets separated by 54 cm. Their matter-wave interferometer also promises increased sensitivity in precision tests, for example, when measuring the equivalence principle or measuring gravity. The quantum superposition principle allows massive particles to be delocalized over distant positions. Though quantum mechanics has proved adept at describing the microscopic world, quantum superposition runs counter to intuitive conceptions of reality and locality when extended to the macroscopic scale1, as exemplified by the thought experiment of Schrodinger’s cat2. Matter-wave interferometers3, which split and recombine wave packets in order to observe interference, provide a way to probe the superposition principle on macroscopic scales4 and explore the transition to classical physics5. In such experiments, large wave-packet separation is impeded by the need for long interaction times and large momentum beam splitters, which cause susceptibility to dephasing and decoherence1. Here we use light-pulse atom interferometry6,7 to realize quantum interference with wave packets separated by up to 54 centimetres on a timescale of 1 second. These results push quantum superposition into a new macroscopic regime, demonstrating that quantum superposition remains possible at the distances and timescales of everyday life. The sub-nanokelvin temperatures of the atoms and a compensation of transverse optical forces enable a large separation while maintaining an interference contrast of 28 per cent. In addition to testing the superposition principle in a new regime, large quantum superposition states are vital to exploring gravity with atom interferometers in greater detail. We anticipate that these states could be used to increase sensitivity in tests of the equivalence principle8,9,10,11,12, measure the gravitational Aharonov–Bohm effect13, and eventually detect gravitational waves14 and phase shifts associated with general relativity12.

Quantum superposition at the half-metre scale

We show that light-pulse atom interferometry with atomic point sources and spatially resolved detection enables multiaxis (two rotation, one acceleration) precision inertial sensing at long interrogation times. Using this method, we demonstrate a light-pulse atom interferometer for $^{87}\mathrm{Rb}$ with 1.4 cm peak wave packet separation and a duration of $2T=2.3\text{ }\text{ }\mathrm{s}$. The inferred acceleration sensitivity of each shot is $6.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}g$, which improves on previous limits by more than 2 orders of magnitude. We also measure Earth's rotation rate with a precision of $200\text{ }\text{ }\mathrm{nrad}/\mathrm{s}$.

https://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.111.083001

Multiaxis Inertial Sensing with Long-Time Point Source Atom Interferometry

Inertial sensors relying on atom interferometry offer a breakthrough advance in a variety of applications, such as inertial navigation, gravimetry or ground- and space-based tests of fundamental physics These instruments require a quiet environment to reach their performance and using them outside the laboratory remains a challenge Here we report the first operation of an airborne matter-wave accelerometer set up aboard a 0g plane and operating during the standard gravity (1g) and microgravity (0g) phases of the flight At 1g, the sensor can detect inertial effects more than 300 times weaker than the typical acceleration fluctuations of the aircraft We describe the improvement of the interferometer sensitivity in 0g, which reaches 2 x 10-4 ms-2 / \surdHz with our current setup We finally discuss the extension of our method to airborne and spaceborne tests of the Universality of free fall with matter waves

https://hal.archives-ouvertes.fr/hal-00834705/document

Detecting inertial effects with airborne matter-wave interferometry

We present a cold atom gravimeter dedicated to field applications. Despite the compactness of our gravimeter, we obtain performances (sensitivity 42 microGal/Hz^0.5, accuracy 25 microGal) close to the bestgravimeters. We report gravity measurements in an elevator which led us to the determination of the Earth's gravity gradient with a precision of 4 E. These measurements in a non-laboratory environment demonstrate that our technology of gravimeter is enough compact, reliable and robust for field applications. Finally, we report gravity measurements in a moving elevator which open the way to absolute gravity measurements in an aircraft or a boat.

Compact cold atom gravimeter for field applications

We present a cold atom gravimeter dedicated to field applications. Despite the compactness of our gravimeter, we obtain performances (sensitivity 42 μGal/Hz1/2, accuracy 25 μGal) close to the best gravimeters. We report gravity measurements in an elevator which led us to the determination of the Earth's gravity gradient with a precision of 4E. These measurements in a non-laboratory environment demonstrate that our technology of gravimeter is enough compact, reliable, and robust for field applications. Finally, we report gravity measurements in a moving elevator which open the way to absolute gravity measurements in an aircraft or a boat.

Measuring gravity from an aircraft is essential in geodesy, geophysics and exploration. It fills a gap between satellite techniques which have a low spatial resolution and traditional ground measurements which can only be performed on ground in accessible areas. Today, only relative sensors are available for airborne gravimetry. This is a major drawback because of the calibration and drift estimation procedures which lead to important operational constraints and measurement errors. Here, we report an absolute airborne gravimeter based on atom interferometry. This instrument has been first tested on a motion simulator leading to gravity measurements noise of 0.3 mGal for 75 s filtering time constant. Then, we realized an airborne campaign across Iceland in April 2017. From repeated line and crossing points, we obtain gravity measurements with an estimated error between 1.7 and 3.9 mGal. The airborne measurements have also been compared to upward continued ground gravity data and show differences with a standard deviation ranging from 3.3 to 6.2 mGal and a mean value ranging from − 0.7 to − 1.9 mGal.

/pdf/absolute-airborne-gravimetry-with-a-cold-atom-sensor-j6sa3fjwgi.pdf

Absolute airborne gravimetry with a cold atom sensor

We present a local measurement of gravity combining Bloch oscillations and atom interferometry With a falling distance of 08 mm, we achieve a sensitivity of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}\phantom{\rule{028em}{0ex}}\text{g}$ with an integration time of 300 s No bias associated with the Bloch oscillations has been measured A contrast decay with Bloch oscillations has been observed and attributed to the spatial quality of the laser beams A simple experimental configuration has been adopted where a single retroreflected laser beam performs atom launches, stimulated Raman transitions, and Bloch oscillations The combination of Bloch oscillations and atom interferometry can thus be accomplished with an apparatus no more complex than a standard atomic gravimeter

Yannick Bidel

Papers

Detecting inertial effects with airborne matter-wave interferometry

Compact cold atom gravimeter for field applications

Compact cold atom gravimeter for field applications

Absolute airborne gravimetry with a cold atom sensor

Local gravity measurement with the combination of atom interferometry and Bloch oscillations