In a double slit experiment with a single electron, a very thin film of fluorescent material that emits a photon whenever an electron passes through is placed on one of the slits to check which slit the electrons goes through. Describe the resulting pattern on the detecting screen if the experiment is repeated many time
The instant you observe the electron it is there, but the instant later, where is it?
No change in the detecting screen will be observed. It is as if electrons are passing through both slits.
In a double-slit experiment with a single electron, the presence of a very thin film of fluorescent material on one of the slits allows us to determine which slit the electron passes through. This setup introduces the concept of "which-path" information, which generally disrupts the interference pattern observed on the detecting screen.
Typically, without any which-path measurement, the double-slit experiment demonstrates an interference pattern on the detecting screen. This pattern arises due to the wave-like nature of the electron, where it exhibits both particle and wave behavior. The electron behaves as a wave that passes through both slits simultaneously and interferes with itself, resulting in regions of constructive and destructive interference on the screen.
However, when the thin film of fluorescent material is present, and it emits a photon upon detecting the electron passing through one of the slits, it provides a measurement of the electron's path. This measurement collapses the electron's wavefunction and destroys the interference pattern, as the electron is now treated as a particle with a definite path.
Therefore, if the experiment is repeated many times, the resulting pattern on the detecting screen would resemble two distinct regions corresponding to the individual slits rather than the interference pattern. Each electron would be observed as a single dot or mark on the screen, indicating which slit it passed through.
It's important to note that this disruption of the interference pattern is a consequence of the observation process in quantum mechanics. It illustrates the delicate balance between the wave-like and particle-like behavior of quantum particles and provides insight into the nature of quantum uncertainty and measurement.