Determinism and Quantum Mechanics : some proposed tests

Lorcán O. Conlon, Angus Walsh, Yuhan Hua +5 more

Abstract Quantum mechanics has withstood every experimental test thus far. However, it relies on ad-hoc postulates which require experimental verification. Over the past decade there has been a great deal of research testing these postulates, with numerous tests of Born’s rule for determining probabilities and the complex nature of the Hilbert space being carried out. Although these tests are yet to reveal any significant deviation from textbook quantum theory, it remains important to conduct such tests in different configurations and using different quantum states. Here we perform the first such test using coherent states of light in a three-arm interferometer combined with homodyne detection. Our proposed configuration requires additional assumptions, but importantly allows us to use quantum states which exist in a larger Hilbert space compared to previous tests. For testing Born’s rule, we find that the third order interference is bounded to be κ = 0.002 ± 0.004 and for testing whether quantum mechanics is complex or not we find a Peres parameter of F = 1.0000 ± 0.0003 (F = 1 corresponds to the expected complex quantum mechanics). We also design and implement a test of Glauber’s theory of optical coherence.

Grete Hermann

Niall Shanks

Immo Söllner, Urbasi Sinha, Christophe Couteau +4 more

This study sets out to test Born's rule to verify the fundamental postulates of quantum mechanics. This study looks for any deviation from the quantum mechanical triadditivity of three mutually exclusive events. Experimentally, a "three-path interference" that can not be explained through the Born interpretation of probabilities is investigated. An upper bound on any such possible deviation from Born's rule is determined.

Mosh� Flato

Björn Schrinski, Stefan Nimmrichter, Benjamin A. Stickler +1 more

We establish an objective scheme to determine the macroscopicity of quantum superposition tests with mechanical degrees of freedom. It is based on the Bayesian hypothesis falsification of a class of macrorealist modifications of quantum theory, such as the model of continuous spontaneous localization. The measure uses the raw data gathered in an experiment, taking into account all measurement uncertainties, and can be used to directly assess any conceivable quantum mechanical test. We determine the resulting macroscopicity for three recent tests of quantum physics: double-well interference of Bose-Einstein condensates, Leggett-Garg tests with atomic random walks, and entanglement generation and read-out of nanomechanical oscillators.