Possibility of realizing Bussey's thought experiment on collapse of the wave function at the microscopic level

Kouichi Toyoshima*, Takasi Endo and Yutaka Hirayoshi
Faculty of Science and Engineering, University of Saga, Saga 840-8502, Japan
* attendee

abstract

Feasibility of an experiment to test if the wave function collapses at the level of microscopic events is discussed. Original idea was introduced in 1984 by Bussey as a ‘thought’ experiment. Busseyﾕs proposal is to collide two particles and then let two pairs of scattered and unscattered waves of each particle examined by a pair of Mach-Zehnder type interferometers(MZI). Then, according to the collapse/non collapse assumption different coincidence rates between the different combinations of four outputs of the two MZIs are expected. In our proposition a pair of low-energy electron beams are crossed in a nanometer-size region and collided nearly head-on. Then each combination of two waves scattered at small angles, instead of scattered/unscattered waves in Busseyﾕs proposition, is thrown into the MZI. Each MZI is composed of Moellenstedt biprism as two arms and mirrors, and a thin single-crystal film as a beam splitter/combiner. Orientation of the crystal film and incident angles of electron waves are chosen so that it can make two recombined waves by Bragg scatterings. Geometrical conditions which enables the interference of electron waves were studied for above experimental setups. Another way of testing collapse/non-collapse by observing fringes, instead of using diffracting films, is also discussed.