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Calculate the eigenfunctions for a spin half particle

  • #1

Homework Statement


Spin can be represented by matrices. For example, a spin half particle can be described by the following Pauli spin matrices
[tex] s_x = \frac{\hbar} {2} \begin{pmatrix} 0 & 1 \\ 1 & 0 \end{pmatrix} , s_y = \frac{\hbar} {2} \begin{pmatrix} 0 & -i \\ i & 0 \end{pmatrix} , s_z = \frac{\hbar} {2} \begin{pmatrix} 1 & 0 \\ 0 & -1 \end{pmatrix} [/tex]

Calculate the corresponding eigenfunctions which we will denote as ɑ- and β-eigenfunctions corresponding to spin 1/2 particles. Further show that sj can be determined by the commutation of the other two matrices sn and sm , n,m≠j.

Homework Equations




The Attempt at a Solution


I have calculated the eigenvalues (first section of the question) of all three matrices to be ±ħ/2

I think the diagonal matrix sz has eigenfunctions |α> = (1; 0) and |β> = (0; 1)
From that I found the eigenfunctions of sx and sx to be
|x+> = |α> + |β> & |x-> = -|α> + |β> and
|y+> = -i|α> + |β> & |y-> = i|α> + |β> respectively

But I'm not entirely sure I'm correct...
 

Answers and Replies

  • #2
DrClaude
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From that I found the eigenfunctions of sx and sx to be
|x+> = |α> + |β> & |x-> = -|α> + |β> and
|y+> = -i|α> + |β> & |y-> = i|α> + |β> respectively
Apart from normalization, these are correct.
 
  • #3
Thanks @DrClaude

Any ideas as to how I show the commutation part of the question?
 
  • #4
DrClaude
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Any ideas as to how I show the commutation part of the question?
Calculate the commutator for each pair of operators and see what you get.
 

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