Dual species matter qubit entangled with light
  We propose and demonstrate an atomic qubit based on a cold $^{85}$Rb-$^{87}$Rb isotopic mixture, entangled with a frequency-encoded optical qubit. The interface of an atomic qubit with a single spatial light mode, and the ability to independently address the two atomic qubit states, should provide the basic element of an interferometrically robust quantum network. 
S.-Y. Lan, S. D. Jenkins, T. Chaneliere, D. N. Matsukevich, C. J.   Campbell, R. Zhao, T. A. B. Kennedy, and A. Kuzmich