Extreme beam attenuation in double-slit experiments: Quantum and subquantum scenarios

•Combining high and low probability densities of intensity hybrids in double-slit setups.•Connecting to beam attenuation techniques in neutron interferometry.•Our “superclassical” model predicts the same results as standard quantum theory.•Showing previously unexpected new effects in intensity hybrids for low transmissivity.•Our explanation is based on the nonlinearity of the probability density currents.

Combining high and low probability densities in intensity hybrids  , we study some of their properties in double-slit setups. In particular, we connect to earlier results on beam attenuation techniques in neutron interferometry and study the effects of very small transmission factors, or very low counting rates, respectively, at one of the two slits. We use a “superclassical” modeling procedure which we have previously shown to produce predictions identical with those of standard quantum theory. Although in accordance with the latter, we show that there are previously unexpected new effects in intensity hybrids for transmission factors below a≲10−4a≲10−4, which can eventually be observed with the aid of weak measurement techniques. We denote these as quantum sweeper effects, which are characterized by the bunching together of low counting rate particles within very narrow spatial domains. We give an explanation of this phenomenology by the circumstance that in reaching down to ever weaker channel intensities, the nonlinear nature of the probability density currents becomes ever more important, a fact which is generally not considered–although implicitly present–in standard quantum mechanics.