Optical frequency metrology: Quantum sensing on ground and in space

Abstract

Atomic quantum sensors enable precise measurements of inertial forces and serve as stable and accurate frequency references. Their unrivaled resolution and the suppression of long-term drifts makes them ideal candidates not only for a large variety of terrestrial applications, but also motivates their development for spaceborne metrological tasks. In my presentation, I will review our endeavor of developing atomic quantum sensors for space. I will present an atomic gravimeter whose resolution is improved by quantum entanglement. Within the INTENTAS project, we develop this technology towards space applications, as can be tested in Hannover´s Einstein Elevator. The Einstein Elevator offers experimental tests under microgravity for up to 4s, while the experiment undergoes a controlled acceleration during a 20 m high parabolic trajectory. Furthermore, I will outline the development of optical lattice clocks. Optical lattice clocks offer the measurement of time and frequency with unprecedented stability and accuracy. However, their development for space applications poses significant challenges regarding compactification, robustness and autonomous operation. I will outline our approach and review possible application scenarios for Earth observation, navigation, and global time and height referencing.