(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A 10-eV electron is incident on a potential barrier of height 25eV and width 1 nm.

Use equation 6-76 to calculate the order of magnitude of the probablity that the electron will tunnel through the barriers.

Repeat with width .1nm

2. Relevant equations

Equation 6-76 is:

E = Electron Enegy

V = Potential

a = width

T = 16 (E/V) (1- (E/V) e^{-2aw}

To get w

w = sqrt ( 2m (V-E)) / hbar

where m = mass of electron

hbar= 6.582119 x 10^{-16}eV*s

3. The attempt at a solution

I know these are the right answers ( they are given)

4.95 x 10^{-13}and 0.197

Seems to be a simple plug and chug problem, but, However, when I plug the known values into my calculator, the expontential goes to 0. I dont know if my dimensional analysis matched up or not (im using hbar in ev*s though), or maybe my calc is limited in the size of the numbers it can display.

Also, IM not sure what 'order of magnitude' means in the context of the question.

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# Homework Help: Quantum Barrier Potential (should be easy)

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