- #1

neural_jam

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Ok, so this example question is in my lecture notes:

"For a 1-D quantum well, 5nm width, 2eV barrier height, calculate the number of energy levels in the well."

So the equation given is a familiar one:

[tex]E_n=\frac{n^2 \pi^2 \hbar^2}{2 m L^2}[/tex]

and he also said [tex]E_n=2 \times 1.6 \times 10^{-19} J[/tex]

Now, in the lecture [tex]n^2[/tex] came out to be 134, but I keep getting ~1.9, so I'm using the wrong units somewhere or something, because otherwise it's a pretty simple 'plug and chug' exercise..!

also, I'm using

[tex]\hbar = 6.582 \times 10^{-16} eVs[/tex]

[tex]m = 0.511MeV[/tex]

Can anyone help? :-s

-Jam

## Homework Statement

"For a 1-D quantum well, 5nm width, 2eV barrier height, calculate the number of energy levels in the well."

## Homework Equations

So the equation given is a familiar one:

[tex]E_n=\frac{n^2 \pi^2 \hbar^2}{2 m L^2}[/tex]

and he also said [tex]E_n=2 \times 1.6 \times 10^{-19} J[/tex]

## The Attempt at a Solution

Now, in the lecture [tex]n^2[/tex] came out to be 134, but I keep getting ~1.9, so I'm using the wrong units somewhere or something, because otherwise it's a pretty simple 'plug and chug' exercise..!

also, I'm using

[tex]\hbar = 6.582 \times 10^{-16} eVs[/tex]

[tex]m = 0.511MeV[/tex]

Can anyone help? :-s

-Jam

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