I have a quesion regarding a quantum physics assignemnt, I wonder what units I should use when calculating the transmission coefficient of a quantum barrier problem.(adsbygoogle = window.adsbygoogle || []).push({});

I have got the following expression:

[tex]

T = \frac{4(E+V_0)}{(2E+V_0)cos^2a\sqrt{\frac{2m}{\hbar^2}(E-V_0)} + (E-V_0+\frac{E(E+V_0)}{E-V_0}+2\sqrt{E(E+V_0)})sin^2a\sqrt{\frac{2m}{\hbar^2}(E-V_0)}}

[/tex]

where

T = the transmission coefficient

E = the energy of an incoming electron = 2.1 eV

[itex]V_0[/itex] = a potential = 1.5 eV

a = a point along the x-axis = 12 angstrom (= [itex]12*10^{-10}[/itex] m)

m = the mass of the electron (= [itex]9.109*10^{-31}[/itex] kg)

[itex]\hbar[/itex] = [itex]1.0546*10^{-34}[/itex] Js or [itex]6.582*10^{-16}[/itex] eVs.

I don't know if I should translate all values in the whole expression into SI units, or if I somehow can use the values given in the assignment in eV and angstrom directly?

If I use the eV- and angstrom values, I guess it is wrong to use the kg-value of the electronmass in the [itex]\sqrt{\frac{2m}{\hbar^2}(E-V_0)}[/itex]-expressions.

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# Homework Help: Units in a quantum barrier problem

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