Calculate the eigenfunctions for a spin half particle

AI Thread Summary
The discussion focuses on calculating the eigenfunctions for a spin half particle using Pauli spin matrices. The eigenvalues of the matrices are determined to be ±ħ/2, with the eigenfunctions for sz identified as |α> = (1; 0) and |β> = (0; 1). The eigenfunctions for sx and sy are derived as |x+> = |α> + |β>, |x-> = -|α> + |β>, |y+> = -i|α> + |β>, and |y-> = i|α> + |β>. The user seeks clarification on demonstrating the commutation relations between the spin operators, with a suggestion to calculate the commutator for each operator pair. The thread emphasizes the importance of normalization for the eigenfunctions.
borndisaster
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Homework Statement


Spin can be represented by matrices. For example, a spin half particle can be described by the following Pauli spin matrices
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}

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...
 
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borndisaster said:
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.
 
Thanks @DrClaude

Any ideas as to how I show the commutation part of the question?
 
borndisaster said:
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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