Quantized energy in infinite potential well

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
9 replies · 5K views
rozan977
Messages
9
Reaction score
0
How does energy become quantized in an infinite potential well??
 
Physics news on Phys.org
Honestly from a mathematical standpoint it comes about due to the boundary conditions of the Schrödinger equation for an infinite potential well.
 
rozan977 said:
How does energy become quantized in an infinite potential well??

The proper functions (eigenfunctions) of the Hamiltonian are sin(πnz) where z is the dimensionless length z=x/L. The proper values (eigenvalues) are proportional to (πn)2.

Any, I repeat, any wave inside the well can be decomposed in a sum of proper waves with some amplitudes. In general case the wave energy is not certain but dispersed. Only in the eigenstates the energy is certain.
 
rozan977 said:
How does energy become quantized in an infinite potential well??

As the frequencies of a string in a guitar [tex]E_n = h v_n = n h v[/tex]


620px-Harmonic_partials_on_strings.svg.png
 
That is through (periodic) boundary conditions.
 
For this aspect, Pythagoras was the first to study a problem of QM mechanics.

http://img523.imageshack.us/img523/5874/pitagoradagafuriotheorixk5.jpg
 
Last edited by a moderator:
Feldoh said:
Honestly from a mathematical standpoint it comes about due to the boundary conditions of the Schrödinger equation for an infinite potential well.

But what if the solution we assume of Schrödinger equation be in exponential form??
 
rozan977 said:
But what if the solution we assume of Schrödinger equation be in exponential form??

it is completely equivalent.
 
rozan977 said:
But what if the solution we assume of Schrödinger equation be in exponential form??

In order to satisfy the boundary conditions the two complex exponentials have to have certain coefficients that make their sum to be sin(pi*n*x/L).