title: Approaching the Heisenberg Limit without Single-Particle Detection.
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.
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Davis
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Bentsen
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Monika
authors.initials: M
authors.lastname: Schleier-Smith