Quantum rotation sensing by BEC in an atom chip waveguide

We describe an improved quantum rotation sensor utilizing BEC interferometry based on the Sagnac effect. The interferometry is conducted in a weak AC time-orbiting potential trap generated by a novel atom chip. By incorporating the chip, we anticipate sensitivity improvements to our prior result of 10 μrad/s. The chip will be operated in air, mounted near a 1-mm thick silicon vacuum wall. Atoms in the vacuum will be positioned near the wall using optical tweezers. Evaporative cooling in the hybrid optical/magnetic trap will produce a BEC, which will then be adiabatically transferred to the pure magnetic trap. As in our previous work, Bragg splitting will generate circularly propagating matter-wave packets within the waveguide for interferometry. The rotation-induced phase shift is extracted from the interference pattern using absorption imaging. Two different atom chip designs are considered, both producing cylindrically symmetric TOP trap potentials. The chips are engineered to suppress eddy currents, enhancing measurement precision, while also enabling precise tuning and characterization of trap anharmonicities. This experiment will establish a foundation for a compact, chip-scale quantum rotation sensor based on matter-wave interferometry, with direct applications in inertial navigation systems.