Exploring Two Photon Bound States: Insights from Recent Research | Physics World

In summary, scientists have created two photon bound states, or "molecules of light", by mediating the interaction between photons and electrons in ultracold Rubidium atoms. These bound states exhibit characteristics similar to normal molecules, such as an average distance between the photons and energy levels. However, they are best regarded as a new kind of pseudo-particle and their "bound" characteristic may just be a result of their proximity and the medium's control over their progress. Further research is needed to fully understand the nature of these two photon bound states.
  • #1
Claustral
5
0
With great interest I read an article about a paper where scientists were able to create two photon bound states ("molecules of light").

http://physicsworld.com/cws/article/news/2013/sep/26/physicists-create-molecules-of-light

I was quite astonished since light normally does not self-interact (apart from Delbrück scattering, which is strictly speaking no direct interaction). Of course, in this experiment the interaction between the two photons is not direct either, but mediated via the interaction of the photons with the electrons in the ultracold Rubidium atoms. Still I wonder, how such a two photon bound state is described theoretically and how far one can go with the analogue of a normal molecule: Can one define an average distance between these two photons? It sounds at least strange, since photons are normally not localizable, are they? Are these states photons at all or merely mixed photon-electron states? How long can this bound state in principle live? Are there energy levels such as a electron bound to a nucleus has them?
 
Physics news on Phys.org
  • #2
This is a coherent interaction between a highly excited atom (Rydberg state) and the coherent forward scattering of the follow-on photon.

It is a fine example of very "non-linear optics", and depends upon the states of the matter. It is probably best regarded as a new kind of pseudo-particle.

You can read the Nature article abstract here: http://www.nature.com/nature/journal/v502/n7469/full/nature12512.html
 
Last edited by a moderator:
  • #3
Thanks for the answer. I got access to the original article and it helps a lot.
 
  • #4
When I read this it seemed like what they are describing is 2 photons with the appearance of being bound, not actually bound. Their progress through the medium is controlled by the medium in such a way that they exit together, but then there is no "bound" characteristic other than their proximity.

Am I missing something obvious?
 
  • #5
meBigGuy said:
When I read this it seemed like what they are describing is 2 photons with the appearance of being bound, not actually bound. Their progress through the medium is controlled by the medium in such a way that they exit together, but then there is no "bound" characteristic other than their proximity.

Am I missing something obvious?

It reads that way to me, too. The the first photon parties with more than one atom at a time, creating the state and slowing the speed of the photon. Then they seem to suggest that the second photon stays behind the first because the state offers a different index of refraction than the surrounding cloud. Are they suggesting a lower index of refraction is fooling photon #2 into following as closely as possible to slower photon #1?
 

1. What is two photon bound state?

A two photon bound state is a quantum state in which two photons are entangled and bound together, exhibiting properties that cannot be explained by the individual properties of the photons.

2. What recent research has been done on two photon bound states?

Recent research has focused on gaining a better understanding of the properties and behavior of two photon bound states, including studying their stability, lifetime, and potential applications in quantum information processing.

3. How are two photon bound states created?

Two photon bound states can be created through a process called spontaneous parametric down-conversion, in which a high energy photon is split into two lower energy photons that become entangled and bound together.

4. What insights have been gained from studying two photon bound states?

Insights gained from studying two photon bound states include a better understanding of quantum entanglement and its potential applications in quantum communication and computation.

5. What are the potential applications of two photon bound states?

Potential applications of two photon bound states include quantum cryptography, quantum teleportation, and quantum computing, as they are highly sensitive to external interference and can be used for secure information transmission.

Similar threads

  • Quantum Physics
Replies
7
Views
1K
  • Quantum Physics
Replies
1
Views
2K
  • Advanced Physics Homework Help
Replies
6
Views
1K
  • Quantum Interpretations and Foundations
3
Replies
79
Views
5K
Replies
8
Views
2K
  • Quantum Interpretations and Foundations
4
Replies
135
Views
8K
  • High Energy, Nuclear, Particle Physics
Replies
4
Views
3K
  • Quantum Physics
Replies
32
Views
9K
Back
Top