Tutorial on Combinatorial Optimization on Quantum Computers (Sept 2021)

[@martinpoitrinal5618]

what a masterpiece, best explanation on qaoa i've seen so far

[@Листочек-ч3к]

Thank you so much for understandeble and beautiful code! Awsome video!

[@boutatdriss4041]

A lot of thanks for this fantastic lecture.

[@lifelikepixel]

Hi Ruslan, thanks for this tutorial It was very interesting. I have one question though. In minute 40:17, when you discretize the unitary operator U(T,0), are you not assuming that the Hamiltonian H(t), evaluated at different times, commute? From my point of view, that can not be assumed. Thanks again,

[@petermontgomery4597]

Nice video on QAOA and love the tutorial too!

[@tjdgmlchl6305]

49:00

[@maxwellsdaemon7]

Hello again. I want to understand what you meant at 1:04:10. It sounded like you wanted to get the best solution from the QAOA, but actually what it looks you did in the code is a brute-force search (by calling min and using the result of the maxcut_obj function), so the graph you obtained is not the result of QAOA, it seems to me. Did I misinterpret what you did (vs what you said)?

[@RuslanShaydulin]

You are correct, the brute-force is getting the solution for the underlying MaxCut problem (i.e. a binary string encoding variable assignment to the two parts).

[@kl8078]

Hi Ruslan Shaydulin, You did a very nice presentation. I have a problem at 16'53'', index i = 1, ....n, but |x> = |x_0 .... x_n>, that will be a total of n+1 elements, so the matrix Z_i Z_j in the sum has dimension of 2^n+1 * 2^n+1, right?

[@RuslanShaydulin]

I think you're right, should be |x> = |x_0 .... x_{n_1}>

[@amandeepbhatia1707]

Any update or tutorial on error mitigation for qaoa ?

[@RuslanShaydulin]

Not yet, but I will be speaking about the error mitigation work at IEEE Quantum Week on Fri Oct 22nd (qce.quantum.ieee.org/technical-papers-program/#technicalpapersoverview).

[@amandeepbhatia1707]

@@RuslanShaydulin I went through your papers. Thank you for your reply. I think I will not be able to make it to IEEE quantum week.