Reading about Young's double slit experiment for electrons, it is stated that the diffraction pattern is observed when both slits are open but not for a single slit (I suppose this is equivalent to there being no diffraction pattern when an observer is placed to measure which slit the electron passes through).
And yet a diffraction pattern is observed for light passing through a single slit. I have not read about this being observed for electrons. Why is this so? I would think that the wave functions describing all matter particles are of the same form and would behave in the same way. I did think that perhaps it had to do with not being able to create small enough slits to observe the electron diffraction pattern, but that cannot be true because the spacing of fringes for two slits and one wide slit is the same if the distance between slits is the same as the width of the single slit. So if we can create small enough slits to space them d apart, then surely we can create a single slit of width d?