Quantum spreading of polarization

If you measure it at 90 degrees, you could measure it later and still find it at 90 degrees. If you measure it at 45 degrees, you could measure it later and find it with probability 1/2 at 0 degrees and probability 1/2 at 90 degrees.In summary, after measuring the position of a particle sharply, it will spread out according to the Heisenberg uncertainty principle. However, the polarization of a photon does not spread out independently after being measured. This is because there are non-commuting polarization elements that become uncertain after the initial measurement. So, the polarization will remain at the measured angle unless another measurement is made.
  • #1
jimgraber
Gold Member
247
18
After we measure the position of a particle fairly sharply, it “spreads out” or the uncertainty grows according to the Heisenberg uncertainty principle. After we measure the polarization of a photon, does it spread out, too? If not, why not? If so, how fast?
TIA
Jim Graber
 
Physics news on Phys.org
  • #2
jimgraber said:
After we measure the position of a particle fairly sharply, it “spreads out” or the uncertainty grows according to the Heisenberg uncertainty principle. After we measure the polarization of a photon, does it spread out, too? If not, why not? If so, how fast?
TIA
Jim Graber

The polarization, once known, does not independently evolve with time (other than continuing oscillation). There will be non-commuting polarization elements which will become completely uncertain as a result of the initial measurement. So if you measure photon polarization to be at 0 degrees, in principle you could measure it later and see it at the same polarization (assuming travel in a vacuum).
 

Related to Quantum spreading of polarization

1. What is quantum spreading of polarization?

Quantum spreading of polarization is a phenomenon that occurs in quantum systems where the polarization of a particle is not well-defined and can change over time due to interactions with its environment.

2. Why is quantum spreading of polarization important in quantum systems?

Quantum spreading of polarization is important because it can affect the behavior of quantum particles and can lead to unexpected outcomes in experiments. It is also a fundamental concept in understanding the dynamics of quantum systems.

3. How does quantum spreading of polarization differ from classical polarization?

In classical systems, the polarization of a particle is well-defined and does not change over time. However, in quantum systems, the polarization can change due to interactions with its environment, leading to quantum spreading of polarization.

4. Can quantum spreading of polarization be controlled or manipulated?

Yes, it is possible to control or manipulate quantum spreading of polarization through techniques such as quantum measurements and quantum control. These techniques can be used to minimize or enhance quantum spreading, depending on the desired outcome.

5. What are some applications of understanding quantum spreading of polarization?

Understanding quantum spreading of polarization is essential for various applications in quantum information processing, quantum computing, and quantum cryptography. It is also crucial in studying and developing new quantum technologies and materials.

Similar threads

Replies
32
Views
2K
  • Quantum Physics
Replies
3
Views
355
Replies
7
Views
792
Replies
2
Views
844
Replies
28
Views
692
  • Quantum Physics
Replies
2
Views
1K
  • Quantum Physics
Replies
17
Views
1K
Replies
5
Views
413
  • Quantum Physics
2
Replies
36
Views
2K
Back
Top