Electron Double-Slit Experiment

Electrons are normally described as particles with: mass, charge, and localized detection events. However, when electrons pass through a double-slit arrangement under suitable experimental conditions, repeated detections can build up an interference pattern. Even when electrons are sent sufficiently sparsely that individual detections occur separately, the accumulated distribution can display interference. Each electron is detected as a localized event. After many events: an interference distribution emerges.

Quantum objects show behaviour that cannot be explained fully by a simple classical “particle-only” model.

If an experiment determines which slit the electron travelled through in a way that destroys the required coherence, the interference pattern is lost.

de Broglie wavelength: **λ=hp Quantum probability idea: P ∝ |ψ₁+ψ₂|² not simply: |ψ₁|²+|ψ₂|²** because an interference cross term can occur.