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Homework Help: Potential Barrier (Q.M. vs Classical Phy.)

  1. Mar 16, 2007 #1
    If you have a Potential Barrier V (width a) and particles incident on left with energy E where E>V, are the following true:

    Classical Physics:
    - All particles will be transmitted past the barrier
    - It cannot be reflected because that would mean it has negative E which is not possible.

    Quantum Mecahnically:
    - Some particles will be reflected (due to there wave nature)
    - Some particles will be transmitted
    - Some particles may exist in the barrier.

    Am I missing anything important?
  2. jcsd
  3. Mar 17, 2007 #2


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    That's correct.
  4. Mar 17, 2007 #3
    Cool thanks.

    To be sure, quantum mechanically a particle is allowed to EXIST in the barrier itself?
  5. Mar 17, 2007 #4

    Meir Achuz

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    No, not inside the wall itself.
    Just as in the classical case, if the wall is between x=0 and x=a, a particle will be in the region 0<x<a for a short period of time.
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