Detecting Rydberg Atoms with Electromagnetically Induced Transparency in a Dual-Isotope Neutral Atom Ensemble

Scalable quantum networking protocols require the verification of the successful transfer of quantum information from one network node to another. In this talk, we present a method of performing a nondestructive measurement in a dual isotope ensemble with 85Rb and 87Rb. The presence of a Rydberg excitation stored in one isotope can be verified by measuring electromagnetically induced transparency (EIT) using a second isotope. Because the two isotopes have different resonant frequencies, each ensemble can be independently controlled without crosstalk. If a Rydberg excitation is present, the EIT signal will be distorted by long range inter-isotope Rydberg interactions. The EIT measurement can be performed quickly with high fidelity to verify the presence of a stored qubit at any point during a quantum information processing operation. We present preliminary results of the nondestructive occupancy verification measurement.