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Quantum Tunneling Experiments

  1. May 31, 2009 #1
    On pages 23 & 24 of the book Superforce by Paul Davies - The unusual
    occurances of electrons or other particles as they approach a barrier
    are described.

    I would like to know what devices are used in these experiments? What
    device shoots out electrons or other particles in a single stream at a
    fairly low rate? Also what kind of barriers are used?

    It is too bad that Davies did not elaborate further on this or give out
    more info. I would guess an electron beam produced by a CRT is too
    energetic or intense for these experiments. Hopefully some one can help
    out here.

  2. jcsd
  3. Jun 1, 2009 #2


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    In a scanning tunneling microscope, the material being probe has a very sharp tip hovering just barely above the surface. A potential bias across the tip-sample causes electrons to tunnel across the vacuum gap between these two.

    In planar tunnel junction, you make layers of a material separated by a thin, insulating region. Again, charge carriers can tunnel across the barrier than a sufficient potential is applied across the barrier.

    etc etc...

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