# Continuous Transition between Classical and Bohm Quantum Pictures for Young's Interference Experiment

Continuous Transition between Classical and Bohm Quantum Pictures for Young's Interference Experiment

This Demonstration explores Young's interference experiment, to show a continuous transition between classical behavior and "quantum motion," as represented by Bohm trajectories in - space. In chemistry and solid-state physics, the scale intermediate between microscopic and macroscopic is called mesoscopic or semi-classical. In the classical case, the trajectories become straight lines crossing the axis of symmetry, in uniform, unaccelerated motion. In the quantum-mechanical limit, the trajectories tend toward the local maxima of the squared wavefunction. These correlate with the plateaus of the quantum potential, and therefore correspond to the bright fringes of the diffraction pattern. The fate of a particle depends sensitively on its initial position. A quantum particle passes through slit 1 or slit 2, but never crosses the axis of symmetry.

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The graphic on the right shows the squared quantum wavefunction and the Bohm trajectories. The graphic on the left shows the position of the particles, the squared quantum wavefunction (blue), the quantum potential (red) and the acceleration (green). The acceleration and quantum potential are scaled to fit.