Quantum Eraser

Quantum Eraser

In quantum mechanics, the quantum eraser experiment is a double-slit experiment that demonstrates several fundamental aspects of the quantum theory, including quantum entanglement and complementarity.

The experiment has two stages:

  1. The experimenter marks through which slit each photon went, without disturbing their movement, and demonstrates that the interference pattern is destroyed. This stage shows that it is the existence of the "which-path" information which causes the destruction of the interference pattern.
  2. The "which-path" information is "erased," whereupon the interference pattern is recovered. It does not matter whether the erasure procedure is done before or after the detection of the photons.

Read more about Quantum Eraser:  Introduction, The Experiment

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