# Illustration Energy levels - infinite square potential well (1d)

A one-dimensional potential well $$W_{\text{pot}}(x)$$ of a certain length with infinitely high potential walls. This means: A particle inside the potential well would need infinite energy to get out of the well.
According to quantum mechanics, the particle (for example an electron) inside the well can only occupy discrete energies $$W_1$$, $$W_2$$, ... $$W_n$$. The six lowest energy levels were drawn in. It is also indicated in the sketch that the energies increase quadratically.