Violation of an extended Wigner inequality with high-angular-momentum states

Abstract

In the study of systems that cannot be described classically, the Wigner inequality, has received only a small amount of attention. In this paper we extend the Wigner inequality -originally derived in 1969 -and show how it may be used to contradict local realism with only coincidence detections in the absence of two-outcome measurements -that is, for any system where only one possible result of a pair of potential outcomes can be registered. It thus encapsulates a much broader class of measurement schemes than could previously violate a local-realistic inequality. This is possible due to an assumption of "extended fairness" on the measurement outcomes, which we posit is highly plausible. We then apply this inequality to a recently constructed setup with access to entangled pairs of photons with very high angular momenta, in which no previously derived local-realistic inequality could successfully be used without making very broad assumptions. To our knowledge this experiment constitutes a violation of local realism with the largest quanta to date. We thus demonstrate the versatility of this inequality under very lossy conditions.

Correlating Space, Wavelength, and Polarization of Light: Spatiospectral Vector Beams

“…On the other hand, the x (y) basis modes have two-lobe structures oriented along 0°and 90°(45°and −45°) 33 and can be distinguished by narrow slits oriented along these directions. 34,35 We implement these slits using the spatial mask already presented in the measurements of Figure 2.…”

“…For the spatial DoF, the z basis is formed by the spatial functions S 1,2 ( r⃗ ) = S 0 ( r⃗ ) e ± i ϕ , which contains counter-rotating spiral wavefronts carrying opposite orbital angular momenta, and indistinguishable intensity profiles. On the other hand, the x ( y ) basis modes have two-lobe structures oriented along 0° and 90° (45° and −45°) and can be distinguished by narrow slits oriented along these directions. , We implement these slits using the spatial mask already presented in the measurements of Figure .…”