Observation of non-classical correlations in sequential measurements of photon polarization

• Published in: New journal of physics Vol. 18; no. 10; pp. 103045 - 103057
• Main Authors: Suzuki, Yutaro, Iinuma, Masataka, Hofmann, Holger F
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 25.10.2016
• Subjects: 03.65.Ta; Correlation analysis; Error analysis; Horizontal polarization; non-classical correlations; non-commuting observables; photon polarization; Photons; Physics; Probability distribution; quantum measurement; quantum state reconstruction; Statistical analysis; Vertical polarization
• ISSN: 1367-2630; 1367-2630
• DOI: 10.1088/1367-2630/18/10/103045

A sequential measurement of two non-commuting quantum observables results in a joint probability distribution for all output combinations that can be explained in terms of an initial joint quasi-probability of the non-commuting observables, modified by the resolution errors and back-action of the initial measurement. Here, we show that the error statistics of a sequential measurement of photon polarization performed at different measurement strengths can be described consistently by an imaginary correlation between the statistics of resolution and back-action. The experimental setup was designed to realize variable strength measurements with well-controlled imaginary correlation between the statistical errors caused by the initial measurement of diagonal polarizations, followed by a precise measurement of the horizontal/vertical polarization. We perform the experimental characterization of an elliptically polarized input state and show that the same complex joint probability distribution is obtained at any measurement strength.