# James Wootton114

May 22 2017 11:04 UTC
May 22 2017 10:49 UTC

There are tasks we could use quantum computers for that would be practically impossible otherwise. And there are tasks that we could do a bit faster on a quantum computer, but it would still be reasonable to use a classical one. 'advantage' could mean either of those. I think it's the absolute dominance over classical computers in the former that people are trying to invoke with 'supremacy'.

The need to use such tainted words is probably an inevitable consequence of trying to explain that one thing is so much better than another. Those words will have been used before in contexts that we don't agree with. Maybe 'transcendence' gets away with it by having kinda spiritual connotations, but that probably makes it a bad fit for science.

Anyways, 'advantage' seems to be the primary option besides supremacy and it isn't too bad. My reservations with it aren't strong enough to try and champion anything else.

May 22 2017 10:27 UTC

'Supremity' could also be an option. It is a word, though a bit archaic. It has the same meanings, but without the baggage. It probably wouldn't be as readily understandable as 'advantage', but 'advantage' doesn't quite mean the right thing.

On the other hand, we could just say "quantum computers outperform classical computers" instead of trying to come up with a fancy *Adjective*$^{ TM}$.

May 09 2017 09:41 UTC
May 09 2017 09:40 UTC
Apr 18 2017 08:29 UTC

Interesting to start getting perspectives from actual end users. But this does focus massively on quantum annealing, rather than a 'true' universal and fault-tolerant QC.

Apr 07 2017 07:26 UTC
Apr 06 2017 08:45 UTC
Apr 04 2017 08:36 UTC
Feb 28 2017 14:11 UTC
Feb 28 2017 08:54 UTC
James Wootton commented on A loophole in quantum error correction

I think I was mostly reacting to where he tries to sell the importance of the work.

>Fault tolerant theorems show that an arbitrary good precision can be obtained using a limited amount of hardware...we unveil the role of an implicit assumption made in these mathematical theorems: the ability to perform quantum measurements with infinite precision.

Feb 27 2017 13:10 UTC
James Wootton commented on A loophole in quantum error correction

Do any fault-tolerance theorems claim to hold for small codes without repeated measurement, as is the case in these supposed counter examples?

Nov 22 2016 09:59 UTC
Nov 18 2016 09:40 UTC
Nov 17 2016 09:16 UTC
Nov 15 2016 09:39 UTC
Oct 19 2016 18:33 UTC
Sep 27 2016 02:00 UTC
Currently, the mainstream approach to quantum computing is through surface codes. One way to store and manipulate quantum information with these to create defects in the codes which can be moved and used as if they were particles. Specifically, they simulate the behaviour of exotic particles known as Majoranas, which are a kind of non-Abelian anyon. By exchanging these particles, important gates for quantum computation can be implemented. Here we investigate the simplest possible exchange operation for two surface code Majoranas. This is found to act non-trivially on only five qubits. The system is then truncated to these five qubits, so that the exchange process can be run on the IBM 5Q processor. The results demonstrate the expected effect of the exchange. This paper has been written in a style that should hopefully be accessible to both professional and amateur scientists.
Sep 14 2016 07:46 UTC

"Ni." would be slightly shorter, but some may find it offensive.

Sep 05 2016 07:47 UTC
Aug 18 2016 16:42 UTC

A video of a talk I gave this morning will be [here][1], if it ever finishes uploading.

[1]: https://youtu.be/I8cMY0AmIY0

Aug 18 2016 02:00 UTC
Current quantum technology is approaching the system sizes and fidelities required for quantum error correction. It is therefore important to determine exactly what is needed for proof-of-principle experiments, which will be the first major step towards fault-tolerant quantum computation. Here we propose a surface code based experiment that is the smallest, both in terms of code size and circuit depth, that would allow errors to be detected and corrected for both the $X$ and $Z$ basis of a qubit. This requires $17$ physical qubits initially prepared in a product state, on which $16$ two-qubit entangling gates are applied before a final measurement of all qubits. A platform agnostic error model is applied to give some idea of the noise levels required for success. It is found that a true demonstration of quantum error correction will require fidelities for the preparation and measurement of qubits and the entangling gates to be above $99\%$.
Jul 11 2016 08:02 UTC
Jul 05 2016 08:54 UTC