we have a particle in an infinite one-dimensional square well potential(adsbygoogle = window.adsbygoogle || []).push({});

[V(x)=0 for 0<x<L and V(x) is infinite otherwise]

and introduce a small potential (perturbation) in the middle of the

square well potential. Then the first order energy correction

for the ground state is 100 times lower than the first order correction

to the first excited state. I dont understand why...

The wave function without the small potential step in the middle

is zero in the middle for the first excited state and maximum in the middle

for the ground state. Has the diffrence in energy corrections something

to do with this?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Simple perturbation theory

**Physics Forums | Science Articles, Homework Help, Discussion**