- 20 Aug 09, 20:29#144215

“ An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says “You’re all idiots”, and pours two beers.
Discuss the sport you love with other motorsport fans
I can not see the image
I got all excited when I read the topic title, I though we we're going to have a genuine Quantum Mechanics discussion
I got all excited when I read the topic title, I though we we're going to have a genuine Quantum Mechanics discussion
The particle in a 1-dimensional potential energy box is the most simple example where restraints lead to the quantization of energy levels. The box is defined as zero potential energy inside a certain interval and infinite everywhere outside that interval. For the 1-dimensional case in the x direction, the time-independent Schrödinger equation can be written as:[38]
- \frac {\hbar ^2}{2m} \frac {d ^2 \psi}{dx^2} = E \psi.
The general solutions are:
\psi = A e^{ikx} + B e ^{-ikx} \;\;\;\;\;\; E = \frac{\hbar^2 k^2}{2m}
or
\psi = C \sin kx + D \cos kx \; (by Euler's formula).
The presence of the walls of the box restricts the acceptable solutions of the wavefunction. At each wall:
\psi = 0 \; \mathrm{at} \;\; x = 0,\; x = L.
Consider x = 0
* sin 0 = 0, cos 0 = 1. To satisfy \scriptstyle \psi = 0 \; the cos term has to be removed. Hence D = 0.
Now consider: \scriptstyle \psi = C \sin kx\;
* at x = L, \scriptstyle \psi = C \sin kL =0\;
* If C = 0 then \scriptstyle \psi =0 \; for all x. This would conflict with the Born interpretation
* therefore sin kL = 0 must be satisfied, yielding the condition.
kL = n \pi \;\;\;\; n = 1,2,3,4,5,... \;
In this situation, n must be an integer showing the quantization of the energy levels.
I got all excited when I read the topic title, I though we we're going to have a genuine Quantum Mechanics discussion
The particle in a 1-dimensional potential energy box is the most simple example where restraints lead to the quantization of energy levels. The box is defined as zero potential energy inside a certain interval and infinite everywhere outside that interval. For the 1-dimensional case in the x direction, the time-independent Schrödinger equation can be written as:[38]
- \frac {\hbar ^2}{2m} \frac {d ^2 \psi}{dx^2} = E \psi.
The general solutions are:
\psi = A e^{ikx} + B e ^{-ikx} \;\;\;\;\;\; E = \frac{\hbar^2 k^2}{2m}
or
\psi = C \sin kx + D \cos kx \; (by Euler's formula).
The presence of the walls of the box restricts the acceptable solutions of the wavefunction. At each wall:
\psi = 0 \; \mathrm{at} \;\; x = 0,\; x = L.
Consider x = 0
* sin 0 = 0, cos 0 = 1. To satisfy \scriptstyle \psi = 0 \; the cos term has to be removed. Hence D = 0.
Now consider: \scriptstyle \psi = C \sin kx\;
* at x = L, \scriptstyle \psi = C \sin kL =0\;
* If C = 0 then \scriptstyle \psi =0 \; for all x. This would conflict with the Born interpretation
* therefore sin kL = 0 must be satisfied, yielding the condition.
kL = n \pi \;\;\;\; n = 1,2,3,4,5,... \;
In this situation, n must be an integer showing the quantization of the energy levels.
See our F1 related articles too!