# Change of basis

1. ### Norman

922
Hello all,

I need some help...
If I know the form of a wavefunction in the $S_z$ basis, say it is spin up, how do I convert that to a wavefunction expressed in the $S_x$ basis? Is there a very simple way to do this?
Thanks

2. ### Norman

922
Anyone???
Do I just rotate the spinor using a rotation operator?
Help?

3. ### Tom Mattson

5,538
Staff Emeritus
You've basically got it. To convert from Sz to Sx, you rotate the state vector p/2 rad about the y-axis.