Physical Review Letters Buchmann, L F, Schreppler, S, Kohler, J, Spethmann, N & Stamper-Kurn, D M 2016, ' Complex Squeezing and Force Measurement Beyond the Standard Quantum Limit ', Physical Review Letters, vol. 117, no. 3, 030801 . https://doi.org/10.1103/PhysRevLett.117.030801