Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help finding electric field for phonon emission.

  1. Feb 11, 2010 #1
    Hello, I seem to be having a problem with an assignment :confused: :

    I need to calculate the electric field at which optical phonons will be emitted. Here's what I have been given:
    1. Semiconductor with effective mass m=0.26*m0.
    2. The optical phonon energy is 50 meV.
    3. The mean scattering time is tau=10e-13 s at 300K.

    There was a hint given in the assignment as well: "the total kinetic energy of an electron is the sum of hte thermal energy and the acquired energy from the field in the form of drift velocity."

    Can I get some guidance here? I am reviewing my notes but some help would be appreciated. Thanks in advance.
  2. jcsd
  3. Jul 8, 2010 #2
    an EM wave can interact with a phonon mode of the same frequency and wavevector. As I remember it, frequency of 10**13 sec. corresponds to phonon energy of 40meV.

    I doubt if any crystal can have an optical phonon energy of 50 meV? that may be a good news for much higher Tc.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook