100 years on the Sagnac merry-go-round


The Sagnac effect enables the measurement of the rotation of a system using counter-propagating waves. It was first demonstrated experimentally using light one hundred years ago by French physicist Georges Sagnac and, in recent years, atom-based systems have begun the exhibit the ability to measure as well as modern laser-based systems. I will introduce the key ideas and history behind these technologies, focusing on the potential of matter wave-based interferometers. I will show how the accumulation of the relative phase difference between matter wavepackets will be observable as discrete jumps in future high-precision ultracold atom experiments using Bose-Einstein condensates or degenerate Fermi gases.