R.
Vijay
Bergeal, N. ., Schackert, F. ., Metcalfe, M. ., Vijay, R. ., Manucharyan, V. E., Frunzio, L. ., … Devoret, M. H. (2010). Phase-preserving amplification near the quantum limit with a Josephson ring modulator. Nature, 465, 64-U70. http://doi.org/10.1038/nature09035