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Tunneling w/ unknown energy

  1. Oct 10, 2010 #1
    1. The problem statement, all variables and given/known data

    The work function (energy needed to remove an electron) of gold is 5.1 eV. Two pieces of gold (at the same potential) are separated by a distance L.

    For what value of L will the transmission probability for an electron to cross from one to the other be T ≈ 10-3? Assume that G = 1 in the formula for the tunneling probability.

    2. Relevant equations

    T [tex]\approx[/tex] G*e-2KL
    where K=2*pi*[tex]\sqrt{((2*m)/h2)*(Uo-E))}[/tex]

    T: Tunneling Probability
    m: Electron Mass
    Uo: Potential (the work function in this case)
    E: Energy of the electron
    L: Length of the potential barrier to tunnel
    h: Planck's constant

    3. The attempt at a solution

    It seems to be a simple plug and chug, but how do I find the energy to use in the (Uo-E) part in the tunneling equation?
     
  2. jcsd
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