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Is stokes vector can be a quantum state? 
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#1
Feb2912, 04:00 PM

P: 2

Is a stokes fourvector like (1 1 0 0) being horizontal polarized vector can be treated as a quantum state? If the answer is yes, this state can be used to construct density matrix?



#2
Mar112, 11:44 AM

P: 669

Yes and yes.
http://en.wikipedia.org/wiki/Polarization_%28waves%29 The coherency matrix is nothing else than a density matrix. 


#3
Mar112, 01:19 PM

P: 2

But coherency matrix is a 2χ2 matrix, which can be constructed by stokes parameters. The density matrix constructed by stokes vector itself would be a 4χ4 matrix.
ρ=(1 1 0 0)χ(1 1 0 0) If this 4χ4 matrix is a density matrix, how can I measure the degree of polarization of this density matrix? 


#4
Mar112, 05:12 PM

P: 669

Is stokes vector can be a quantum state?
The Stokes vector has 4 real components.
The coherency matrix is a 2x2 complex matrix built from the unity matrix and the 3 Pauli matricies. That also makes 4 free variables. You can easily construct the density matrix from the Stokes vector and vice versa. Born and Wolf's textbook has a pretty good chapter on that. 


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