Transmission coefficient in a barrier penetration.

[simon8502]

An electron having total energy E=4.46 eV approaches a rectangular energy barrier with U=5.02 eV and L=949 pm. Calculate this probability, which is the transmission coefficient.


I thought this would be an easy one, given that
T=e^-2GL
and
G=$$\sqrt{\frac{2m(U-E)}{H}}$$ where H is the reduced Planck's constant

I just plugged in the numbers,
U=5.02eV
E=4.46eV
L=949E-12m
m=9.109E-31kg

I found that T=7.18E-4, which is apparently wrong. Can anyone point out where I went wrong?


PS. oops I just realized that I should've put this in the homework help section. First time posting. Sorry!

 

[fzero]

Did you account for the units? Your energies are in eV, while your mass and length are in SI units. There are some factors to take into account so that the quantity $$GL$$ is properly dimensionless.

 

[simon8502]

Found that that the hbar value I used was wrong by a few decimals. Thanks for the help :)