# How can I sort photons by spin?

• jartsa
In summary, photon spin is a quantum mechanical property that refers to the intrinsic angular momentum of a photon. It can be sorted in a laboratory setting through spin filtering and can be useful in various scientific experiments and technologies. It is possible to sort individual photons by spin using advanced techniques such as quantum state tomography, but there are limitations such as potential loss of photons and difficulty with higher energy or shorter wavelength photons.

#### jartsa

I want to split a photon beam with no net angular momentum into two beams in both of which the sum of photon spins is not zero.

A polarizing beamsplitter will separate an unpolarized beam into two beams, one vertically polarized, and one horizontal. By using quarter wave plates in each arm, you can turn the horizontally polarized light into right-circular polarization, and the vertically polarized light into left-circular polarization. The input beam would have no net angular momentum, and the output beams would have spin not equal to zero.

## 1. How do you define photon spin?

Photon spin is a quantum mechanical property that refers to the intrinsic angular momentum of a photon. It is a fundamental characteristic of a photon and is always either +1 or -1.

## 2. Can photons be sorted by spin in a laboratory setting?

Yes, it is possible to sort photons by spin in a laboratory setting through a process called spin filtering. This involves using specialized materials or devices that can selectively allow photons with a certain spin to pass through while blocking others.

## 3. What is the purpose of sorting photons by spin?

Sorting photons by spin can be useful in various scientific experiments and technologies. It can help in studying the behavior of photons and their interactions with matter, as well as in developing advanced technologies such as quantum computing and communication.

## 4. Is it possible to sort individual photons by spin?

Yes, it is possible to sort individual photons by spin using advanced techniques such as quantum state tomography. This involves measuring the spin state of each photon using specialized detectors and then sorting them accordingly.

## 5. Are there any limitations to sorting photons by spin?

While sorting photons by spin can be a powerful tool, it also has its limitations. For example, the process of sorting can result in a loss of photons and can only be done with a certain degree of accuracy. Additionally, the process may be more challenging for photons with higher energies or shorter wavelengths.