Trapped atom dynamics in overlapping ⁸⁵Rb and ⁸⁷Rb ensembles

We present progress on a dual species quantum memory in overlapping ensembles of cold ⁸⁵Rb and ⁸⁷Rb. The overlapping ensembles can be independently manipulated with resonant light and exhibit strong, controllable inter-ensemble interactions mediated by Rydberg blockade. We characterize the properties of the crossed-beam dipole trap in which the ensembles are confined and discuss differences in the trapped atom dynamics between single isotope and dual isotope loading. Measurement fidelity is compared before and after implementing optical pumping to a stretched state and reducing the size of the measurement beam waist to that of the trapped ensembles. The dual-species quantum memory offers new capabilities for quantum networking applications.