- #1
brooke1525
- 15
- 0
Homework Statement
I'm given the eigenvalue equations
L[tex]^{2}[/tex]|[tex]\ell[/tex],m> = h[tex]^2\ell(\ell + 1)|\ell[/tex],m>
[tex]L_z[/tex]|[tex]\ell[/tex],m> = m|[tex]\ell[/tex]
[tex]L_{\stackrel{+}{-}}[/tex]|[tex]\ell[/tex],m> = h[tex]\sqrt{(\ell \stackrel{-}{+} m)(\ell \stackrel{+}{-} m + 1)}[/tex]|[tex]\ell[/tex], m [tex]\stackrel{+}{-}[/tex] 1>
Compute <[tex]L_{x}[/tex]>.
Homework Equations
Know that [tex]L_x = (1/2)(L_+ + L_-)[/tex].
The Attempt at a Solution
Need to compute <[tex]\ell[/tex],m|[tex]L_x[/tex]|[tex]\ell[/tex],m>.
= (1/2)(<[tex]\ell[/tex],m)([tex]L_+[/tex] + [tex]L_-[/tex])([tex]\ell[/tex],m>)
= (1/2)(<[tex]\ell[/tex],m|[tex]L_+[/tex]|[tex]\ell[/tex],m> + <[tex]\ell[/tex],m|[tex]L_-[/tex]|[tex]\ell[/tex],m>)
I don't think I have a good grasp on how to work with dirac notation, so this as far as I can get before I get stuck. Thanks in advance for any help!