Basic Quantum Algorithms | Hacker News Reader

Basic Quantum Algorithms

arxiv.org

56 pointsrbanffy7 comments

This seems to be a good review of "classical" quantum algorithms, i.e. based on the circuit model and assuming ideal quantum hardware, but I think it misses the key thing that is happening in quantum computing right now.

At least to me, a former quantum computing researcher who has just switched back to quantum computing after a decade in traditional computing, the thing that made me decide that now is the time to move is that there is an emergence of new algorithms focusing on making the most of the noisy intermediate scale quantum (NISQ) computers that we can actually build today.

One of the prominent examples is the variational quantum eigensolver (VQE) algorithms [0, 1] which are hybrid quantum-classical algorithms which can often serve as replacements for the phase estimation algorithms described in the final section of TFA.

[0]: https://www.nature.com/articles/ncomms5213.pdf [1]: https://iopscience.iop.org/article/10.1088/1367-2630/18/2/02...

For those who are interested, this lecture was sent to me as an overview of quantum computation for people like me: people who know how to code and know some basic linear algebra.

It goes deeper than the pop-sci articles about "doing all combinations at once" but remains accessible and by the end you understand entanglement and can read some Q# code.

https://www.youtube.com/watch?v=F_Riqjdh2oM

This is a very clear and technical text, something I have been looking for some time (to teach from). However, this should not be read on its own because it does not explain why the algorithms work beyond that the algebra works. We need to think a bit more about the design decisions behind the algorithms.

Nevertheless I am quite happy that the Shor's algorithm part includes probability analysis at the undergraduate level, something missing from a lot of other texts.

It is amazing how far ahead of practice the theory of quantum algorithms has gotten, and it will be even more amazing when the first commercial quantum computer is built and they all suddenly get used. I wonder if there is any precedent for this?

Perhaps Ada Lovelace, publishing the first computer algorithms in 1843. She wrote them for Babbage's Analytical Engine, which was never built.

But I have no idea whether her work was used on the first functioning computers, rather than being just an example of what was possible. Maybe the QC situation is unique.

> In this work, all those remarkable [quantum] algorithms are described in detail with a focus on the circuit model.

Very nice, this is not just an article but a 106 page book.

Does anyone know if there is any demand for quantum coders (with physics background?) or it is still exclusive?

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