
Arrow of time and its reversal on the IBM quantum computer - espeed
https://www.nature.com/articles/s41598-019-40765-6
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panic
Previous discussion:
[https://news.ycombinator.com/item?id=19378567](https://news.ycombinator.com/item?id=19378567)

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stallmanite
Always fun waiting for Scott Aaronson to explain why the latest QC paper is
bullshit. Until then can any Quantum Information experts here provide some
background? I read the paper but don’t trust my intuition with these kind of
things.

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xwdv
Essentially it seems like they are exploring ways in which for certain
computations a solution can be found before the computation has actually
finished, approaching something like O(1) performance.

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gus_massa
No, the experiment takes "2t" time, "t" in the initial part and "t" in the
backward part. I wrote more details in
[https://news.ycombinator.com/item?id=20491309](https://news.ycombinator.com/item?id=20491309)

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inflatableDodo
> _The exemplary outcome probabilities 𝑃𝑖𝑗=|⟨𝑏𝑖𝑏𝑗|𝜓̃ 0⟩|2 and 𝑃𝑖𝑗𝑘=|⟨𝑏𝑖𝑏𝑗𝑏𝑘|𝜓̃
> 0⟩|2, 𝑖,𝑗,𝑘=0,1 obtained in a real experiment for the 2- and 3-qubit models
> are shown on the Fig. 3E. One can see that the probability for observing the
> correct final state |0…0⟩ is less than 100% and for 2- and 3-qubit
> experiment are given by 85.3±0.4% and 49.1±0.6% correspondingly._

Does this mean that the 3 qubit model is predicted to only get the correct
result for less than half the times it is asked?

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devxpy
Relevant data structures lecture :

[https://m.youtube.com/watch?v=T0yzrZL1py0](https://m.youtube.com/watch?v=T0yzrZL1py0)

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meow_mix
Can anyone break this down into something non-clickbaity?

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craftinator
I think a non clickbaity version of this article would look something like the
following:

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nickpsecurity
Lmao. Your reply should be the top comment on a lot of articles that get
filtered before they make it to the front page. Apparently, some that do make
it, too.

