# Quantum harmonic oscillator

1. Jun 10, 2010

### glederfein

Hello.
I am trying to use the following equation:
$$a\left|\psi_n\right\rangle=\sqrt{n}\left|\psi_{n-1}\right\rangle$$
(where a is the "ladder operator").

What happens when I substitute $$\psi_n$$ with $$\psi_0$$?

2. Jun 10, 2010

### glederfein

oops, sorry for the silly question...
of course I will get 0.