Polarization and entanglement of photons 09/05/2020

Pascal DUBOIS

Key words: photon; polarization; model; entanglement; quantum; entangled photons; theorem; Bell inequalities; wave theory.

In the note entitled "Gravitational field, Fundamental Principle of Dynamics and Quantum Mechanics"[1] , we showed that the concept of wave-particle duality could be expressed in a classical way by introducing a pilot wave that has a physical reality. This wave is attached to the gravitational field and obeys an equation close to the Schrödinger equation.

Another basic concept of quantum mechanics is entanglement. For a pair of particles that are entangled with respect to a given property (e.g. photon polarization), the corresponding state vector is non-separable: it cannot be factorised into a tensor product of two vectors, each defining the state of a single particle. As a result, whatever the distance separating two entangled particles, a measurement made on one particle influences the other particle.

The non-local nature of quantum mechanics has given rise to much discussion [2] . Following repeated experiments [3] , quantum entanglement is accepted as a physical reality, although no explanation has been proposed other than the possibility of the existence of non-separable states, which is not prohibited by the quantum formalism.

In this note, we show that a new approach to the notion of photon polarization makes it possible to recover the basic results of quantum mechanics. The probabilization of the results does not reflect a fundamental indeterminacy inherent in the photon, but comes from taking into account a polarization model that introduces a dispersion around a principal direction. The polarization state of the photons is not modified by the polarizer, but the latter selects a cohort of photos whose distribution depends on the orientation of the polarizer.

Although this approach cannot be described as non-local, it allows us to recover the results of experiments carried out on entangled photons . We explain why there is no contradiction with Bell's theorem.

Finally, the proposed model for photon polarization makes it possible to establish a link with classical wave theory, which has yet to be developed.

[1] https://www.aimer-la-physique.com

[2] including those linked to the EPR paradox (introduced by Einstein, Podolsky and Rosen in 1935).

[3] and in particular those of Alain Aspect on pairs of photons entangled in polarisation (1980-1982)