Dimension of \lambda constant in \delta potential

In summary, the time independent Schroedinger equation in a delta potential with a given constant ##\lambda >0## can be expressed as ##-\frac{\hbar^2}{2m}\frac{d^2}{d x^2}\psi(x)-\lambda \delta(x)\psi(x)=E\psi(x)##. To find the dimension of ##\lambda##, we can use the dimension of ##V(x)## which is given as [V(x)]=ML^2T^{-2} and the one dimensional problem's dimension of ##\psi(x)## which is [\psi(x)]=L^{-\frac{1}{2}}. From this, it can be concluded that the dimension of
  • #1
LagrangeEuler
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Time independent Schroedinger equation in ##\delta## potential ##V(x)=-\lambda \delta(x)##, where ##\lambda >0## is given by
[tex]-\frac{\hbar^2}{2m}\frac{d^2}{d x^2}\psi(x)-\lambda \delta(x)\psi(x)=E\psi(x)[/tex].
How to find dimension of ##\lambda##? Dimension of ##V(x)## is
[tex][V(x)]=ML^2T^{-2}[/tex].
Because it is one dimensional problem dimension of ##\psi(x)## is
[tex][\psi(x)]=L^{-\frac{1}{2}}[/tex].
Is then also
[tex][\delta(x)]=L^{-\frac{1}{2}}[/tex]?
 
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  • #2
The dimension of ##\psi## is irrelevant. From ##\int dx\,\delta(x)=1## it follows that the dimension of ##\delta## is ##L^{-1}##. From that, the dimension of ##\lambda## should be easy.
 
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  • #3
Demystifier said:
The dimension of ##\psi## is irrelevant. From ##\int dx\,\delta(x)=1## it follows that the dimension of ##\delta## is ##L^{-1}##. From that, the dimension of ##\lambda## should be easy.
Thank you very much.
 
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