1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Free electrons

  1. Nov 2, 2009 #1
    Hi all

    Is a free electron (with momentum p = hbar k) still free if it is in an electric field? I.e., is the momentum is given as p = hbar k?
  2. jcsd
  3. Nov 2, 2009 #2
    No, it is not free any more. No, the kinetic momentum is different and may well be uncertain because there is no k any more. It depends on the form of the external electric field: uniform, Coulomb, etc., as well as on the problem you solve: stationary states or transitions.
    Last edited: Nov 2, 2009
  4. Nov 2, 2009 #3
    Hi there,

    Under the action of an electric field, the momentum of a free electron will vary.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook