# Are the two wave functions from a double slit (in single particle int) entangled?

1. Jul 16, 2011

### San K

http://en.wikipedia.org/wiki/Quantum_entanglement#cite_note-0"

Is there an experiment where bucky balls are entangled?

Many of us have heard about bucky balls showing single particle interference in a double slit experiment. However I have not heard of them being entangled.

I read the reference [1] for the above quote and it is referring to double slit as well, there is no mention of bucky balls being entangled.

or

Is the above quote saying that the two waves-functions in a double slit are entangled?

Last edited by a moderator: Apr 26, 2017
2. Jul 16, 2011

### Jacques_L

"buckyballs" is not in my dictionnary. Please be more explicit.

In most experiments with double slits - but some very finely tuned and synchronized lasers - the same quanton interferes with itself. The same photon, with the rare exceptions quoted above. The same electron, with no exceptions, the same neutron, with no exception : they are fermions. The only one condition at arrival on the absorber is that both branches of path give the same phase at $2k\pi$.
Of course one quanton - whichever it be, photon or electron or else - has only one absorber, and you only retrieve the familiar macroscopic picture of interference fringes by repeating on many of these shoots.

Last edited by a moderator: Apr 26, 2017
3. Jul 16, 2011

### San K

Hello Jacques,

to answer your question......buckyballs are fullerene/carbon molecules.

http://en.wikipedia.org/wiki/Fullerene" [Broken]

however my question is more about the following:

1. scientist have been able to show single particle (self-)interference with carbon molecules. these are thousands of times larger than photons/electrons etc.

however I have not heard of carbon molecules being entangled. yet the Wikipedia link above mentions entanglement. so I am thinking are they referring to single particle interference and somehow relating that to entanglement?

2. in other words, is there a relationship between coherence (i.e. same phase) and entanglement?

we know, and as you said above, coherence (at 2kpi) is needed for interference.

3. on a separate topic: you got me curious, why would very finely tuned and synchronized lasers, not show interference?

Last edited by a moderator: May 5, 2017
4. Jul 16, 2011

### Jacques_L

They do :
http://webcache.googleusercontent.com/search?q=cache:AZtqb35tanAJ:hal.archives-ouvertes.fr/docs/00/56/39/08/PS/CRAS_Laser_IFRAF_11_02_06_arxiv.ps+cache:7VN0_F2KezgJ:www.lkb.ens.fr/Publications,549+ultra+cold+atoms+Kastler+laser&cd=9&hl=fr&ct=clnk&gl=fr&source=www.google.fr [Broken]
Otherwise in PS format :
http://hal.archives-ouvertes.fr/docs/00/56/39/08/PS/CRAS_Laser_IFRAF_11_02_06_arxiv.ps

Last edited by a moderator: May 5, 2017
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