Abstract
We propose an approach to quantum phase estimation that can attain precision near the Heisenberg limit without requiring single-particle-resolved state detection. We show that the “one-axis twisting” interaction, well known for generating spin squeezing in atomic ensembles, can also amplify the output signal of an entanglement-enhanced interferometer to facilitate readout. Applying this interaction-based readout to oversqueezed, non-Gaussian states yields a Heisenberg scaling in phase sensitivity, which persists in the presence of detection noise as large as the quantum projection noise of an unentangled ensemble. Even in dissipative implementations—e.g., employing light-mediated interactions in an optical cavity or Rydberg dressing—the method significantly relaxes the detection resolution required for spectroscopy beyond the standard quantum limit.
- Received 14 August 2015
DOI:https://doi.org/10.1103/PhysRevLett.116.053601
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