'Quantum Cheshire Cat' as Simple Quantum Interference

Abstract

In a recent work, Aharonov et al. suggested that a photon could be separated from its polarization in an experiment involving pre- and post-selection [New J. Phys 15, 113015 (2013)]. They named the effect 'quantum Cheshire Cat', in a reference to the cat that is separated from its grin in the novel Alice's Adventures in Wonderland. Following these ideas, Denkmayr et al. performed a neutron interferometric experiment and interpreted the results suggesting that neutrons were separated from their spin [Nat. Commun. 5, 4492 (2014)]. Here we show that these results can be interpreted as simple quantum interference, with no separation between the quantum particle and its internal degree of freedom. We thus hope to clarify the phenomenon with this work, by removing these apparent paradoxes.

5 pages, 3 figures

References in corpus (6)

• Ultrasensitive Beam Deflection Measurement via Interferometric Weak Value Amplification
• Experimental realization of Wheeler's delayed-choice GedankenExperiment
• Geometric phase in weak measurements
• Observation of a classical cheshire cat in an optical interferometer
• Interaction between light and matter: A photon wave function approach
• Postselection induced entanglement swapping from a vacuum--excitation entangled state to separate quantum systems