Hi everyone.(adsbygoogle = window.adsbygoogle || []).push({});

I am now learning the perturbation theory in QM.

and I have encountered something that puzzles me.

from

http://en.wikipedia.org/wiki/Perturbation_theory_(quantum_mechanics [Broken])

says,

"...Since the overall phase is not determined in quantum mechanics, without loss of generality, we may assume <n(0)|n> is purely real. Therefore, <n(0)|n(1)>=-<n(1)|n(0)>, and we deduce..."

What do you mean by "the overall phase is not determined in quantum mechanics" ?

I especially emphasize "in quantum mechanics". Does this mean that we cannot find a specific value for the phase by quantum calculation?

I appreciate your help!

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

Dismiss Notice

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!

# Phase in quantum mechanics

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