Register to reply

Density operator quantum mechanics

Share this thread:
Jan7-13, 02:26 PM
P: 1
I have the following situation: About the polarization of the photon, I introduce the basis:

Horizontal polarization $|\leftrightarrow>=\binom{1}{0}$
Vertical polarization $|\updownarrow>=\binom{0}{1}$

The density matrix in this problem is:

$$\rho =\frac{1}{2}\begin{pmatrix}
1+\xi _{1} & \xi_{2}-i\xi _{3}\\
\xi_{2}+i\xi _{3} & 1-\xi _{1}

The Stokes parameters are: $\xi _{1}, \xi _{2}, \xi _{3}$

The probability that if the photon has got lineal polarization whose axis forms an angle $\theta$ with de horizontal is:

$$|w>=cos\theta |\leftrightarrow>+sin\theta|\updownarrow>$$

$$ P_{\theta}=<w|\rho|w>=\frac{1}{2}\left ( 1+\xi_{1}cos(2\theta)+\xi_{2}sin(2\theta) \right )$$

Is there any value of the [Stokes parameters]( for which this probability is zero?
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution
Phys.Org News Partner Science news on
Bees able to spot which flowers offer best rewards before landing
Classic Lewis Carroll character inspires new ecological model
When cooperation counts: Researchers find sperm benefit from grouping together in mice

Register to reply

Related Discussions
Operator in quantum mechanics Advanced Physics Homework 3
Quantum Mechanics Operator Advanced Physics Homework 6
Quantum mechanics momentum operator Quantum Physics 6
Quantum mechanics - operator problem Advanced Physics Homework 3
Quantum Mechanics Positional Operator Advanced Physics Homework 5