How to Produce Entanglement

This week we just do a quick revisit of last week's topic: Entanglement! Let's head to the lab with Jacques Carolan from the Center for Quantum Photonics to see how he builds the entangled states he uses in his quantum computer.

[GeoffryGifari]

of all the things i've learned about entanglement, how to make them in the real world is one of the things i feel are the least discussed... thank you for this

[john-alanpascoe]

Really cool to see an actual quantum experiment set-up, rather than the usual analogies / thought experiments. I still find entanglement a hard thing to wrap my head around, but your videos are helping me to get there.

[philo]

Thank you. This is the video I was looking for. As you say at the beginning they always talk about the entangled particles, but you never know how they got entangled in the first place. Even though it’s difficult to fully understand it, as a non-physicist, it definitely helped me visualize it a little better. Keep it up.

[michellefernandez]

This is one of the few videos that helped me visualize and understand quantum entanglement. Concise yet technical.. Brilliant!

[Nitrogearhead]

Why does this video have only 2000 views but flat earth videos have hundreds of thousands of views..?

[Dwayne_Green]

"Spooky action at a distance"

[jhyland]

That guy is really good at explaining complex concepts on a basic level without leaving a lot out

[anthonycollins]

on behalf of us mere mortals can you explain it by showing the experiment rather than writing maths, thank you

[theultimatereductionist]

What other particles can be entangled besides photons & electrons?
Can we entangle protons & neutrons? And how?

[werneckpaiva]

Nice presentation. It would be nice if you talk about Delayed-choice quantum eraser. I always see presentations, but no one showing that in practical.

[irwinluck]

I have a 4 questions. Would you be kind enough to answer each of them.
1) When 2 particles are entangled and one particle spin is measured is it true that both particles superposition collapses at the same time and the two particles have opposite spins?
2) When the measurement ends do both particles revert back to a superposition. Are they still entangled?
3) If they are, can one of the entangled particles be measured again collapsing both there superpositions to have opposite spins?
4) What experiments have been done to answer these questions?

[evenaicantfigurethisout]

4:31 "you don't know whether they were created in the first crystal or the second crystal". why couldn't the photon have been affected by BOTH crystals? the first one jiggles it a little and then the second one jiggles it a bit more.


BTW, when he says the photon is "created by the crystal" does he mean in the Feynman QED sense where the electron in the crystal absorbs the photon then some other electrons in the crystal re-emits two photons etc etc.?

[FriedrichBoettger]

I've read volumes of stuff about 'entanglement', but I never saw anybody entangle something. This was revelatory. Your question about 'uncertainty' was a propos. Took me 8 years to find somebody to explain it, but I think I get it--to the extent that it can be gotten. Thanks.

[breyrey]

Content is amazing and wonderful but you need a gimble with your camera my friend. Folks who have motion sickness are throwing up a minute into the video. :-)

[theultimatereductionist]

6:45 "There's some physical process, but we don't know what it is." I'd called that "spooky".

[glutinousmaximus]

Well, I got entangled with a married woman. Then she went and told him which broke the wave function. Then he came round and broke my nose.

[arijitdas]

Excellent video. Finally got an idea of how you can produce an entangled state with photons.

[dmo]

This was amazing! I would've loved to have seen visual results from the laser experiment, even if they were simple/unattractive plots showing proof of horizontal vs. vertical photon measurements, just as long as it showed proof of entanglement :)

[DavidTJames-yqdr]

Thanks for the vid. The content, and your access to the lab is something I could.never get unless I built it myself... which is why this showed up in my search for DIY Particle Entanglement.
Thanks for the education and demonstration.

[tylerblok]

Holy cow so many questions! Is it possible to put entangled particles back together? Or combine two separate unmeasured entangled particles together to affect the state of their respective entangled partners? Great video btw!