| dc.description.abstract | In a paper by Araújo et al., the quantum switch was first theoretically described
with the process matrix formalism where the authors claim that it is “a genuine example
of ’indefinite causal order’ “. This means A superposition of event E before F (E ≺ F)
with F before E (F ≺ E). The quantum switch was first experimentally implemented
by Procopio et al., where the authors claim that it is “the first realization of a ’superposition
of causal order’ “. In this thesis, a Bohmian Mechanical toy model is used to
describe the experimental realization presented in the paper by Procopio et al. The relevant
parts of the experiment are first described by quantum mechanics, thereafter the
description with Bohm’s theory is made. In Bohmian Mechanics, particles always have
definite positions, and are guided by the wave function. The particle’s trajectories of
the particles follow from the guiding equation. The Bohmian trajectories are computed
close to the first beam splitters of the Mach-Zehnder interferometer, giving insights into
the trajectories for the whole experimental setup. Both the Quantum Mechanical and
the Bohmian Mechanical descriptions are completely in line with the experimental outcome.
Based on these descriptions, it turns out that the experimental implementation
is compatible with causal order from the perspective of both Quantum Mechanics and
Bohmian Mechanics. Instead of a superposition of the same two events with different
causal orders, we find that there are four different events. Even the assumption of 2
events underlying the process matrix formalism in the paper by Araújo et al. seems
to be broken in the experiment. It therefore seems that the claim of indefinite causal
order by Procopio et al. may be too strong. | en_US |
