To test this, you can lower the intensity until there is never more than one electron between the slits and the screen. You might imagine that the electrons are interfering with one another as any waves do. This can be observed for photons or electrons-for now, let us concentrate on electrons. Both patterns are probability distributions in the sense that they are built up by individual particles traversing the apparatus, the paths of which are not individually predictable.īoth patterns build up statistically as individual particles fall on the detector. Double-slit interference for electrons (a) and photons (b) is identical for equal wavelengths and equal slit separations. First, we note that these patterns are identical, following d sin θ = mλ, the equation for double-slit constructive interference developed in Photon Energies and the Electromagnetic Spectrum, where d is the slit separation and λ is the electron or photon wavelength.įigure 2. Consider the double-slit patterns obtained for electrons and photons in Figure 2. Let us explore what happens if we try to follow a particle. It is somewhat disquieting to think that you cannot predict exactly where an individual particle will go, or even follow it to its destination. Those who developed quantum mechanics devised equations that predicted the probability distribution in various circumstances. There is a certain probability of finding the particle at a given location, and the overall pattern is called a probability distribution. After compiling enough data, you get a distribution related to the particle’s wavelength and diffraction pattern. However, each particle goes to a definite place (as illustrated in Figure 1). The idea quickly emerged that, because of its wave character, a particle’s trajectory and destination cannot be precisely predicted for each particle individually. The overall distribution shown at the bottom can be predicted as the diffraction of waves having the de Broglie wavelength of the electrons.Īfter de Broglie proposed the wave nature of matter, many physicists, including Schrödinger and Heisenberg, explored the consequences.
Each electron arrives at a definite location, which cannot be precisely predicted. The building up of the diffraction pattern of electrons scattered from a crystal surface.
0 kommentar(er)
