Abstract

Quantum mechanics is a fundamental theory to describe the physics of microscopic objects, but there are still questions whether this theory is complete or not. One of the fundamental axioms of quantum mechanics is Born’s rule, which claims that the description of nature is probabilistic, with the probability of a given outcome of a measurement given by the absolute square of the amplitude of the wave function: P(r, t) = Ψ^*(r, t)Ψ(r, t) = |Ψ(r, t)|². A characteristic experiment of quantum physics is the Mach-Zehnder interferometer, where a superposition of two beams A and B is created. In this case the probability for the output is: P_AB(r) = |Ψ_A(r) + Ψ_B(r)|² = P_A + P_B + I_AB, where P_A and P_B denote the probability that the particle went through either of path A or B and I_AB = P_AB − P_A − P_B is the so-called interference term. For three or more paths it works similarly and analogously we can define a threepath interference term i_abc = p_abc − p_ab – p_bc – p_ac + p_a + p_b + p_c, which will be identically zero for any interferometer configuration, even asymmetric ones according to Born’s rule.

© 2013 IEEE