Addition of angular momentum MADE EASY!!! (with example for two s=1/2 states)

In this video I will help you understand how to perform the addition of angular momentum in quantum mechanics, with the example of two spin 1/2 particles

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My name is Nick Heumann, I am a recently graduated physicist. I love to teach physics, so I decided to give YouTube a try. English is not my first language, but I hope that you can understand me well enough regardless.
▬ Contents of this video ▬▬▬▬▬▬▬▬▬▬
00:00 Introducing the idea of addition of angular momentum
01:20 Example (two particles of spin 1/2)
02:20 Finding total s and m values
04:00 This is how to do it!!!!
04:20 Finding ket(1,1)
05:40 Finding ket (1,0)
10:10 Finding ket (1,-1)
13:20 Finding ket(0,0)

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[itsfrancyo]

I've a quantum mechanics exam tomorrow, I spent a lot of time trying to understand the addition of angular momentum and searching for good lecture material online but it didn't help. Then I came across your video and, man, you saved me.

[noelwass]

Wonderfully explained. On looking at this closely the only thing not clear to me is why the lowering operator on the tensor product of the two spin 1/2 states is given by the sum of the lowering operators on each component of the tensor product. But that is probably just my ignorance of lowering operator on the tensor product.

[brenthughes]

What software do you use for these wonderful videos?

[raufabid]

Beautifully explained!! But I have a question?

[Artizz]

Great explanation. I have a question related to the addition of angular momenta. If there is an electron with l=2 there are common eigenkets of L^2, S^2, S3 and J^2, L^2, S^2. How can we express one in terms of the other if J=L+S. Example |5/2, 2, 1/2 ; 5/2> = |2, 2; 1/2, 1/2>. How can I argue this?

[lorenzo]

why are both spins 1/2 in the ket (0, 0)? Shouldn´t they have opposite signs?

[brenthughes]

How can I contact you to hire you to instruct me in using the type of software you use?

[themorrigan]

I cant seem ti understand why there is a Stotal = 0 ? arent they both +1/2 particle