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Durham University

Centre for Particle Theory

Research Staff

Publication details for Dr Florent Michel

Robertson, Scott, Michel, Florent & Parentani, Renaud (2017). Assessing degrees of entanglement of phonon states in atomic Bose gases through the measurement of commuting observables. Physical Review D 96(4): 045012.

Author(s) from Durham


We show that measuring commuting observables can be sufficient to assess that a bipartite state is entangled according to either nonseparability or the stronger criterion of “steerability.” Indeed, the measurement of a single observable might reveal the strength of the interferences between the two subsystems, as if an interferometer were used. For definiteness, we focus on the two-point correlation function of density fluctuations obtained by in situ measurements in homogeneous one-dimensional cold atomic Bose gases. We then compare this situation to that found in transonic stationary flows mimicking a black hole geometry where correlated phonon pairs are emitted on either side of the sonic horizon by the analogue Hawking effect. We briefly apply our considerations to two recent experiments.