The Stern-Gerlach experiment - an experiment carried out in 1922 by German physicists Otto Stern and Walter Gerlach . Experience has confirmed the quantization of the projection of the atomic magnetic moment vector , and has also become one of the main arguments in favor of the existence of an intrinsic magnetic moment in electrons and the associated angular momentum - spin .
Initially, the experiment was carried out with silver atoms, but later similar results were obtained for atoms of other metals, as well as for proton and electron beams. These experiments proved the existence of a magnetic moment for the particles under study and showed their quantum nature, showing evidence of the postulates of quantum theory .
The essence of experience
The experiment was as follows: a beam of silver atoms was passed through a highly inhomogeneous magnetic field created by a powerful permanent magnet . When atoms passed through this field, due to the presence of magnetic moments, they were affected by a force depending on the projection of the spin on the direction of the magnetic field , which deflected the atoms flying between the magnets from their original direction of motion. Moreover, if we assume that the magnetic moments of the atoms are oriented randomly (continuously), then a blurred band should appear on the plate located further in the direction of motion of the atoms. However, instead of this, two fairly distinct narrow bands formed on the plate, which testified in favor of the fact that the magnetic moments of atoms along the selected direction took only two definite values, which confirmed the assumption of the quantum-mechanical theory of quantization of the magnetic moment of atoms.
Stern and Gerlach Articles
- Stern, O. Eine direkte Messung der thermischen Molekulargeschwindigkeit. Zeitschrift für Physik , 2: 49–56 (1920).
- Gerlach, W. and Stern, O. Der experimentelle Nachweis des magnetischen Moments des Silberatoms. Zeitschrift für Physik, 8: 110–111 (1921).
- Gerlach, W. and Stern, O. Der experimentelle Nachweis der Richtungsquantelung im Magnetfeld. Zeitschrift für Physik, 9: 349–352 (1922).
- Gerlach, W. and Stern, O. Über die Richtungsquantelung im Magnetfeld. Annalen der Physik 74: 673-699 (1924).
- Gerlach, W. Über die Richtungsquantelung im Magnetfeld II. Annalen der Physik 76: 163–197 (1925).
- Scully, MO, Shea, R., and McCullen, J .. State reduction in quantum mechanics: a calculational example. Physics Reports , 43 (13): 485–498 (1978).
- Mackintosh, AR The Stern-Gerlach experiment, electron spin and intermediate quantum mechanics. European Journal of Physics , 4: 97-106 (1983).
- Scully, MO, Lamb, Willis E., J., and Barut, A. On the Theory of the Stern-Gerlach Apparatus. Foundations of Physics , 17 (6): 575–583 (1987).
- Platt, DE A modern analysis of the Stern-Gerlach experiment. American Journal of Physics , 60 (4): 306-308 (1990).
- Weinert, F. Wrong Theory - Right Experiment: The Significance of the Stern-Gerlach Experiments. Studies in the History and Philosophy of Modern Physics, 26 (1): 75–86 (1995).
- Reinisch, G. Stern-Gerlach experiment as the pioneer — and probably the simplest — quantum entanglement test? Physics Letters A , 259: 427-430 (1999).
- Friedrich, B. and Herschbach, D. Stern and Gerlach: How a Bad Cigar Helped Reorient Atomic Physics. Physics Today , 56 (12): 53–59 (2003).
- Friedrich, B. and Herschbach, D. Stern and Gerlach at Frankfurt: Experimental Proof of Space Quantization. In Trageser, W., editor, Stern-Stunden. Höhepunkte Frankfurter Physik. Frankfurt: University of Frankfurt, Fachbereich Physik (2005).
- Bernstein, J. The Stern-Gerlach Experiment (2010). arXiv : 1007.2435
- Sauer, T. Multiple Perspectives on the Stern-Gerlach Experiment. In Sauer, T. and Scholl, R., editors, The Philosophy of Historical Case Studies, pages 251–263. : Springer (2016).
- Horst Schmidt-Böcking , Lothar Schmidt, Hans Jürgen Lüdde, Wolfgang Trageser, Tilman Sauer . The Stern-Gerlach Experiment Revisited. - arXiv : 1609.09311 .