The first part of this contribution presents an overview of atom interferometry. In a second part, we discuss in greater details the sensitivity of such experiments to weak perturbations and their application to direct test of the electric neutrality of atoms with extreme precision.
Atom interferometers were first realized ten years ago, and since then have evolved from beautiful demonstrations of quantum physics into instruments at the leading edge of precision measurement. In this article we trace the development of atom interferometry, looking at how the physical principles have been put into practice to achieve ground-breaking experiments. We also discuss new atom optical techniques that are becoming available and anticipate the ways in which the consequent improvements will provide new opportunities in metrology and the study of fundamental physics.
Abstract The possibility of interferometry with atoms follows directly from wave particle duality. The wave-like propagation of particles, such as atoms, means that they undergo interference and diffraction in an analogous way to light. This chapter explains how such matter waves have been used in interferometers that measure rotation and gravitational acceler ation to a precision comparable with the best optical instruments. As in many important developments in physics, atom interferometry relies on simple principles-the first part of this chapter uses only elementary optics and the de Broglie relation.
The past three decades have shown dramatic progress in the ability to manipulate and coherently control the motion of atoms. This exquisite control offers the prospect of a new generation of inertial sensors with unprecedented sensitivity and accuracy, which will be important for both fundamental and applied science. In this article, we review some of our recent results regarding the application of atom interferometry to inertial measurements using compact, mobile sensors. This includes some of the first interferometer measurements with cold 39K atoms, which is a major step toward achieving a transportable, dual-species interferometer with rubidium and potassium for equivalence principle tests. We also discuss future applications of this technology, such as remote sensing of geophysical effects, gravitational wave detection, and precise tests of the weak equivalence principle in Space.
Atomic gravimetry measures the gravitional acceleration of an ensemble of identical neutral atoms through the atom interferometry based on Raman two-photon transition, where the Raman lasers are used as “optical ruler" and the identical neutral atoms play the role of test mass and quantum storage of gravity field information. As the novel gravimetry system suffers no mechanical wear and works at a higher repetition rate, atom gravimetry can reach a much better short-term sensitivity than the classical falling-corner-cube counterpart, and the accuracy is reasonably well. Since the very first in-laboratory device built over 30 years ago, atomic gravimetry has matured to a versatile tool that offers both precise and accurate absolute gravity measurement to fundamental research and metrology, such as testing the weak equivalence principle or linking the mass and weight of the test mass in Watt (Kibble) balance. As the current rapid development of compact cold-atom gravimeters, atomic gravimetry is moving out of the laboratory to be used as a quantum enhancement of classical devices in dynamical measurement, such as geophysics survey, inertial navigation and space mission. We review the roadmap for the development of cold-atom absolute gravimetry, highlight recent advances in the dynamical measurement using compact cold atom gravimeters and discuss the associated technological challenges. In the future, with the maturity of its application in dynamical measurement or civil engineering and the innovation in atom interferometry theory, atomic gravimetry could play a more and more important role in our life.