Abstract

Atom interferometers employ precise manipulation of the quantum states of ultracold atom ensembles to probe field variations between the “arms” of the interferometer. The phase of the quantum states continually evolves and accumulates while the atoms interact with laser light pulses used as the interferometer optics and while in free-fall propagation between light pulses. Quantum interference of the atomic matter-waves encodes these fluctuations in the population difference of the quantum states of the ensemble. The leading order phase shift arises from the coupling of the atom acceleration to the natural frequency of the atomic states. For this reason atom interferometers have been built to be precise gravimeters and inertial sensors finding use in tests of Newtons’s constant and the Einstein equivalence principle. They may also serve as a test bed for other precise tests of gravity.

The AION and MAGIS collaborations will utilize this quantum technology in a gradiometer configuration to test fundamental physics and search for ultralight dark matter and gravitational waves in the decihertz frequency range (0.1–1 Hz). In this talk I will develop the influence of a semiclassical space and time dependent Newtonian gravitational field on atom interferometers and demonstrate the potential noise sources long-baseline instruments will come up against. I will also discuss future prospects for relativistic and non-classical tests of gravity with these extremely sensitive sensors.