Atom Interferometry

Since atom interferometers were first realized about 20 years ago, atom interferometry has had many applications in basic and applied science, and has been used to measure gravity acceleration, rotations and fundamental physical quantities with unprecedented precision. Future applications range from tests of general relativity to the development of next-generation inertial navigation systems. This book presents the lectures and notes from the Enrico Fermi school "Atom Interferometry", held in Varenna, Italy, in July 2013. The aim of the school was to cover basic experimental and theoretical aspects and to provide an updated review of current activities in the field as well as main achievements, open issues and future prospects. Topics covered include theoretical background and experimental schemes for atom interferometry; ultracold atoms and atom optics; comparison of atom, light, electron and neutron interferometers and their applications; high precision measurements with atom interferometry and their application to tests of fundamental physics, gravitation, inertial measurements and geophysics; measurement of fundamental constants; interferometry with quantum degenerate gases; matter wave interferometry beyond classical limits; large area interferometers; atom interferometry on chips; and interferometry with molecules. The book will be a valuable source of reference for students, newcomers and experts in the field of atom interferometry.

The field of atom interferometry has expanded rapidly in recent years, and todays research laboratories are using atom interferometers both as inertial sensors and for precision measurements. Many researchers also use atom interferometry as a means of researching fundamental questions in quantum mechanics. Atom Interferometry contains contributions from theoretical and experimental physicists at the forefront of this rapidly developing field. Editor Paul R. Berman includes an excellent balance of background material and recent experimental results,providing a general overview of atom interferometry and demonstrating the promise that it holds for the future. Includes contributions from many of the research groups that have pioneered this emerging field Discusses and demonstrates new aspects of the wave nature of atoms Explains the many important applications of atom interferometry, from a measurement of the gravitational constant to atom lithography Examines applications of atom interferometry to fundamentally important quantum mechanics problems

Due to its impressive sensitivity, long baseline atom interferometry is an exciting tool for tests of fundamental physics. We are currently constructing a 10-meter scale apparatus to test the Weak Equivalence Principle (WEP) using co-located Rb85 and Rb87 atom interferometers. This apparatus aims to improve the current limit on WEP violation 100-fold, which illustrates the power of this technique. This scientific goal sets stringent requirements on the kinematic preparation of the atomic test masses, the interferometer laser wavefront and stability, as well as the electromagnetic and gravitational field homogeneity of the interferometer region. The efforts to control these sources of systematic error are discussed. Additionally, applications of long baseline atom interferometry to space-based sensors for geodesy and gravitational wave detection are presented.

Devised at the beginning of the 20th century by french physicists Charles Fabry and Alfred Perot, the Fabry-Perot optical cavity is perhaps the most deceptively simple setup in optics, and today a key resource in many areas of science and technology. This thesis delves deeply into the applications of optical cavities in a variety of contexts: from LIGO’s 4-km-long interferometer arms that are allowing us to observe the universe in a new way by measuring gravitational waves, to the atomic clocks used to realise time with unprecedented accuracy which will soon lead to a redefinition of the second, and the matterwave interferometers that are enabling us to test and measure gravity in a new scale. The work presented accounts for the elegance and versatility of this setup, which today underpins much of the progress in the frontier of atomic and gravitational experimental physics.

Interferometry, the most precise measurement technique known today, exploits the wave-like nature of the atoms or photons in the interferometer. As expected from the laws of quantum mechanics, the granular, particle-like features of the individually independent atoms or photons are responsible for the precision limit, the shot noise limit. However this “classical” bound is not fundamental and it is the aim of quantum metrology to overcome it by employing entanglement among the particles. This work reports on the realization of spin-squeezed states suitable for atom interferometry. Spin squeezing was generated on the basis of motional and spin degrees of freedom, whereby the latter allowed the implementation of a full interferometer with quantum-enhanced precision.

This book gathers the lecture notes of courses given at Session CVII of the summer school in physics, entitled "Current Trends in Atomic Physics" and held in July, 2016 in Les Houches, France. Atomic physics provides a paradigm for exploring few-body quantum systems with unparalleled control. In recent years, this ability has been applied in diverse areas including condensed matter physics, high energy physics, chemistry and ultra-fast phenomena as well as foundational aspects of quantum physics. This book addresses these topics by presenting developments and current trends via a series of tutorials and lectures presented by international leading investigators.