Weird 'magic' ingredient for quantum computing: Contextuality

Weird 'magic' ingredient for quantum computing: Contextuality

A form of quantum weirdness is a key ingredient for building quantum computers according to new research from a team at the University of Waterloo's Institute for Quantum Computing (IQC).

In a new study published in the journal Nature, researchers have shown that a weird aspect of quantum theory called contextuality is a necessary resource to achieve the so-called magic required for universal quantum computation.

One major hurdle in harnessing the power of a universal quantum computer is finding practical ways to control fragile quantum states. Working towards this goal, IQC researchers Joseph Emerson, Mark Howard and Joel Wallman have confirmed theoretically that contextuality is a necessary resource required for achieving the advantages of quantum computation.

Quantum devices are extremely difficult to build because they must operate in an environment that is noise-resistant. The term magic refers to a particular approach to building noise-resistant quantum computers known as magic-state distillation. So-called magic states act as a crucial, but difficult to achieve and maintain, extra ingredient that boosts the power of a quantum device to achieve the improved processing power of a universal quantum computer.

By identifying these magic states as contextual, researchers will be able to clarify the trade-offs involved in different approaches to building quantum devices. The results of the study may also help design new algorithms that exploit the special properties of these magic states more fully.

"These new results give us a deeper understanding of the nature of quantum computation. They also clarify the practical requirements for designing a realistic quantum computer," said Joseph Emerson, professor of Applied Mathematics and Canadian Institute for Advanced Research fellow. "I expect the results will help both theorists and experimentalists find more efficient methods to overcome the limitations imposed by unavoidable sources of noise and other errors."

Contextuality was first recognized as a feature of quantum theory almost 50 years ago. The theory showed that it was impossible to explain measurements on quantum systems in the same way as classical systems.

Contextuality means that quantum measurements can not be thought of as simply revealing some pre-existing properties of the system under study. That's part of the weirdness of quantum mechanics.

The growth in the quantum computing field is amazing. I look forward to seeing what happens next

a reply to: Margana

The universe is all context and personality. The sooner science evolved into mythology the better.

The ancient cultures of this planet, once again show us how little we know in the modern age.

originally posted by: onequestion
a reply to: Margana

The universe is all context and personality. The sooner science evolved into mythology the better.

The ancient cultures of this planet, once again show us how little we know in the modern age.

It's not just ancient cultures of this planet that show me how little we know, it's all the unknowns out there compared to the known things.

People make these grand claims "Humans are the only intelligent life form on this planet" when we don't know for sure because the only thing we can do is observe other life forms. Now it's getting to the point where we are seeing high intelligence in some species like: Dolphins, Elephants & Octopuses (Octopi)

The growth in the quantum computing field is amazing

no is not.
what i see is, that "they" have no clue how...
they looking for magic

a reply to: ZakOlongapo
It is magic. Their not looking for it their playing with it.

Could be really dangerous.

originally posted by: ZakOlongapo

The growth in the quantum computing field is amazing

no is not.
what i see is, that "they" have no clue how...
they looking for magic

I had a feeling someone would use the word magic that way & I'm hoping you're just being cheeky about it.

So-called magic states act as a crucial, but difficult to achieve and maintain, extra ingredient that boosts the power of a quantum device to achieve the improved processing power of a universal quantum computer.

We are still a step closer because of this finding, sure we still don't have the full picture but that can be said with a LOT of different things. You may not think the growth in quantum computing is not amazing but to me, looking at the old school computers when I was in Grade 3 that were the green screen computers, I'd say the fact that we are trying to do quantum computing is amazing.

a reply to: onequestion
no need for Magic in Electric Universe

but i agree with You.

a reply to: Margana
in my young age i use to be programing on 8 bit computers in Basic language.

miss that time

i understand Your point and i wish You are right, that we are just step from real quantum computing.

but there is problem with "quantum" fields and theories

we just have no clue how some "particles" know about each other in instantaneous time no matter of distance..

or we cant predict how they behave, just because our own thinking is affecting they behavior...

yes "quantum is amazing"!

Imagine turning over a playing card. It will be either a red suit or a black suit -- a two-outcome measurement. Now imagine nine playing cards laid out in a grid with three rows and three columns. Quantum mechanics predicts something that seems contradictory -- there must be an even number of red cards in every row and an odd number of red cards in every column. Try to draw a grid that obeys these rules and you will find it impossible. It's because quantum measurements cannot be interpreted as merely revealing a pre-existing property in the same way that flipping a card reveals a red or black suit.

So in other words it has intelligence. This could explain why quantum particles go where they want when not being observed. In fact, they are so intelligent apparently that it is theorized they know when they are being observed! Now that is magic! So they want to play with magic? Is it coming at us like a dark horse?

originally posted by: Clasper

Imagine turning over a playing card. It will be either a red suit or a black suit -- a two-outcome measurement. Now imagine nine playing cards laid out in a grid with three rows and three columns. Quantum mechanics predicts something that seems contradictory -- there must be an even number of red cards in every row and an odd number of red cards in every column. Try to draw a grid that obeys these rules and you will find it impossible. It's because quantum measurements cannot be interpreted as merely revealing a pre-existing property in the same way that flipping a card reveals a red or black suit.

So in other words it has intelligence. This could explain why quantum particles go where they want when not being observed. In fact, they are so intelligent apparently that it is theorized they know when they are being observed! Now that is magic! So they want to play with magic? Is it coming at us like a dark horse?

((side note: I love your display pic!! Jack, The Pumpkin King!))

I never thought of it that way. Just the possibility that it could be intelligent has me reaffirmed in my belief that we truly know nothing. I hope one day we will but we need people with passion & the time to go for that passion.


I'm just learning about quantum mechanics & other quantum related subjects. I'm not big on science so it takes me a while to fully understand the concept but my boyfriend has been really great at teaching it to me. We haven't gotten around to that subject in a while.

originally posted by: onequestion
a reply to: ZakOlongapo
It is magic. Their not looking for it their playing with it.

Could be really dangerous.

Anything can be called "magic" if you don't really understand how it works. Chemistry/nuclear physics/explosives/alchemy, deep sea drilling, mobile communications.

All they are saying is that if you have a quantum computer that can store 128 Q-bits all intertangled, you need some way of constraining the solution to your question, otherwise you are just going to get 128 random bits every time you check for the answer.

It would not really be magik it is only because we as humans are narrow minded and manipulated and not shown our true technologies...

a reply to: Dicko
When they use the word magic they aren't meaning it like magik,

So-called magic states act as a crucial, but difficult to achieve and maintain, extra ingredient that boosts the power of a quantum device to achieve the improved processing power of a universal quantum computer.

people aren't narrow minded, we just don't have the knowledge because we are too young.

I love that articles like this are now making my own case for how Reality is actually structured. Contextuality is just another word for Contextual Association, and that's established between systems (quantum and "classical") by ramification and precedent. It's not mysterious, but science has been particle-obsessed for quite a while now, so to those people who've been raised to see reality as particle-centric it must seem like magic.

It seems like the more they study the quantum world, the more they need to resort to using new terms and explanations for things they cannot explain. Now they even resort to using the word magic...

All I can say is the more I personally studied quantum mechanics and the like, the more I think science is looking in the wrong direction and going nowhere with this. We may think that we are progressing, but to me it feels like we're in a Mexican stand-off; on side we have science focusing on the wrong subject and on the other side the people who believe so, but are immediately scorned by the scientific community for being ignorant.

I don't have hard evidence of course, but thinking rationally I must admit to myself that as soon as an average person cannot understand the simplest premises of a theory, that the theory must be too complex to be right. I've had so many people explain to me what the quantum world is like with all it's inexplicable mysteries of why some things are happening and they admit it's almost too weird to believe. Not almost for me.

The fact that many theories are today presented as fact is a red flag that people should notice. There is no hard evidence that black holes exist, to give one example, yet it is almost always stated as fact that they do. never is it mentioned that they are based on assumption upon assumption upon assumption.

Any way, to stay on topic, I think a universal quantum computer will never be realised in practice. I don't know how long it will take science to admit they are working on red herrings, but I sincerely hope to live when they do.