Does a Detector Alter Diffraction Patterns in the Two-Slit Experiment?

[rp1220]

In the two slit experiment when which path information is present there is no wave interference pattern such as would be seen with both slits being used. When a single slit is used there is a visible diffraction pattern. Is such a pattern seen when a detector forces a one slit path in the two slit experiment ?

 

[mfb]

With "which path information", you'll still see single-slit interference patterns if the measurement does not measure additional information about the precise position of the particle in the slit.

 

[San K]

In the two slit experiment when which path information is present there is no wave interference pattern such as would be seen with both slits being used. When a single slit is used there is a visible diffraction pattern. Is such a pattern seen when a detector forces a one slit path in the two slit experiment ?

to add to what mfb has already said...

the degree of diffraction/interference is inversely proportional to the degree of precision/probability (of particle/photon location).

its not a yes or no, 1 or 0, interference or no-interference, which-way or no-which-way thing