Electric-field sensing near the surface microstructure of an atom chip using cold Rydberg atoms

The electric fields near the heterogeneous metal-dielectric surface of an atom chip were measured using cold atoms. The atomic sensitivity to electric fields was enhanced by exciting the atoms to Rydberg states that are 108 times more polarizable than the ground state. We attribute the measured fields to charging of the insulators between the atom chip wires. Surprisingly, it is found that although the chip wire currents were turned off before Rydberg excitation, the measured fields were strongly influenced by how the wire currents had been applied. These fields may be dramatically lowered with appropriate voltage biasing, suggesting configurations for the future development of hybrid quantum systems.