Double-Slit Experiment with Electrons

 

Double-Slit Experiment with Electrons

The two-slit experiment is a classical demonstration that was originally performed by Thomas Young in the year 1801 which has a significant implication on our understanding of the nature of light and matter. It demonstrates that light behaves like both waves and a particle. This experiment was originally performed with a monochromatic light shone through two parallel slit openings whose size is in the order of the wavelength of light creating an interference pattern on the screen because of the interference of the two waves through the slits interfering with each other. 

                             

                                         

Later to demonstrate the wave-like behavior of the electron, a beam of electrons was shot through the two-slit openings whose size is in the order of the wavelength of the electron. So, if we allow the electrons to flow through the two-slit openings S1 and S2, an interference pattern is formed on the detector screen. A degree of constructive and destructive interference is formed on the screen, where constructive interference represents the bright fringes and destructive interference represents the dark fringes. On the detector screen, the more intense or brightest fringe is formed at the center of the screen called central maxima with decreasing intensity on either side of the fringe.

Now if we allow a single electron to pass through the two slits, the screen would appear to be very random or there will be no particular pattern formed on the screen. But if we allow the electron to pass through for a longer period of time, an interference pattern would be formed on the screen with a brighter fringe formed at the center of the screen with fewer intensity fringes formed on either side and dark fringes formed in the middle of the bright fringes.