Register to reply

Is stokes vector can be a quantum state?

Share this thread:
ftqpachino
#1
Feb29-12, 04:00 PM
P: 2
Is a stokes four-vector 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?
Phys.Org News Partner Physics news on Phys.org
Engineers develop new sensor to detect tiny individual nanoparticles
Tiny particles have big potential in debate over nuclear proliferation
Ray tracing and beyond
M Quack
#2
Mar1-12, 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.
ftqpachino
#3
Mar1-12, 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?

M Quack
#4
Mar1-12, 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.


Register to reply

Related Discussions
General normalized state for a state vector Advanced Physics Homework 2
Stokes' theorem and unit vector Calculus & Beyond Homework 4
Momentum from position state vector (quantum mechanics) Advanced Physics Homework 4