Young’s double slit experiment

The essential features of the particle-wave duality are clearly illustrated by Young s double-slit experiment. In order to explain all of the observations of this experiment, light must be regarded as having both wave-like and particlelike properties. Similar experiments on electrons indicate that they too possess both particle-like and wave-like characteristics. The consideration of the experimental results leads directly to a physical interpretation of Schrodinger s wave function, which is presented in Section 1.8. 

Figure 1.8 Diagram of Young s double-slit experiment.

Young s double-slit experiment and the Stem-Gerlaeh experiment, as described in the two previous sections, lead to a physical interpretation of the wave function associated with the motion of a particle. Basic to the concept of the wave function is the postulate that the wave function contains all the... 

Figure 3.1 (a) Schematic diagram (not to scale) of Young s double-slit experiment. The narrow slits acts as wave sources. Slits S and S2 behave as coherent sources that produce an interference pattern on screen C. (b) The fringe pattern formed on screen C could look like this. (Reproduced with permission from R. A. Serway Physics for Scientists and Engineers with Modern Physics, 3rd ed, 1990, Saunders, Figure 37.1.)... 

It is observed in Young s double-slit experiment with electrons by Tonomura and coworkers that single electrons observed as dots on the detector screen are accumulated in time to show interference fringes delocalized over the screen [45]. When... 

There is a direct analogy with the fringe pattern that is seen in a Young s double slit experiment, in which the diffraction pattern from two slits produces periodic fringes whose spacing varies inversely with the separation of the slits. The oscillations can also be interpreted in terms of the distortions of the reflected wavefronts in Fig. 7.2 at the Rayleigh angle (Atalar 1979). 

Sofar the imaging results of Fig. 3.1 were discussed in very classical terms, using the notion of a set of trajectories that take the electron from the atom to the detector. However, this description does not do justice to the fact that atomic photoionization is a quantum mechanical proces. Similar to the interference between light beams that is observed in Young s double slit experiment, we may expect to see the effects of interference if many different quantum paths exist that connect the atom to a particular point on the detector. Indeed this interference was previously observed in photodetachment experiments by Blondel and co-workers, which revealed the interference between two trajectories by means of which a photo-detached electron can be transported between the atom and the detector [33]. The current case of atomic photoionization is more complicated, since classical theory predicts that there are an infinite number of trajectories along which the electron can move from the atom to a particular point on the detector [32,34], Nevertheless, as Fig. 3.2 shows, the interference between trajectories is observable [35] when the resolution of the experiment is improved [36], The number of interference fringes smoothly increases with the photoelectron energy. 

Figure 1.7 In Young s double slit experiment, light passes through one slit and then into two slits. The patterns produced by the light proved that light travels as waves rather than particles.

We shall therefore briefly review the experimental efforts in this field throughout the last century. Soon after Louis de Broglie proposed his wave hypothesis for material particles matter wave phenomena were experimentally verified for electrons [Davisson 1927], atoms and dimers [Estermann 1930], and neutrons [Halban 1936 Gahler 1991]. A replica of Young s double-slit experiment with matter waves was demonstrated by Jonsson for electrons [Jonsson 1974], by Zeilinger et al. for neutrons [Zeilinger 1988], by Carnal and Mlynek for atoms [Carnal 1991] and by Schollkopf and Toennies for small molecules and noble gas clusters [Schollkopf 1994 Schollkopf 1996 Bruch 2002],... 

To answer this question, we have set up the experiment as shown in Fig. 1. It resembles very much the standard Young s double-slit experiment. Like its historical counterpart, our setup also consists of four main parts the source, the collimation, the diffraction grating, and the detector. 

The Young s double-slit experiment is the prototype for a demonstration of an optical interference and for all quantitative measurements of so-called first-order coherence. The presence of the interference fringes in the experiment may be regarded as a manifestation of the first-order coherence. 

In Sect. 2.2 the fundamentals of Stellar Interferometry are shown. Starting with the Young s double slit experiment the interferometric observables are explained, this is, the complex visibility function. The data synthesis relevant to the work of this thesis is then presented. Finally, in Sect. 2.3 the concept of Multi-Fourier Transform Interferometry is developed. 

The uncertainty principle can also be demonstrated using a modern-day version of Young s double-slit experiment. Consider that a beam of electrons is fired at a screen having two narrow slits. A suitable detector is placed some distance behind the screen in order to monitor the positions of the electrons. When one of the slits is closed, the electrons striking the detector form a Gaussian distribution exactly opposite the open slit, as might be expected. If this slit is then closed and the other one opened, a second Gaussian distribution appears at the detector opposite the... 

O. Carnal, J. Mlynek Young s double slit experiment with atoms a simple atom interferometer. Rhys. Rev. Lett. 66, 2689 (1991)... 

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