What on earth is a qubit and what does it do?!
Published 10 months ago
I spent some time researching quantum computers... here's what I've come up with :)
Our Southampton based office is a hub of activity, something we are all very proud of. Primarily we're all happily matching talented individuals into exciting organisations, however over a sarnie or whilst making the coffee round, there is of course a nice level of 'chit-chat'. Being a team of IT specialists you can guarantee that about 70% of this 'chit-chat' ia about a new machine learning product, tracking cryptos (notice Crypto(S) not just Bitcoin!) and recently quantum computing.
Quantum computing is computing using quantum-mechanical phenomena, such as superposition and entanglement.
Confused? I was too...sounds like gibberish to me so I'll try again!
The smaller conventional computers get, the more powerful they seem to become: there's more number-crunching ability in my phone, than you'd have found in a room-sized, military computer 50 years ago (I'm reliably informed) Back in the 1960s, Intel co-founder Gordon Moore realized that the power of computers doubles roughly every 18 months—and it's been doing so ever since - known as Moore's Law.
One problem is that the basic switching and memory units of computers, known as transistors, are now approaching the point where they'll soon be as small as individual atoms. If we want computers that are smaller and more powerful, we'll soon need to do our computing in a radically different way. Entering the realm of atoms opens up powerful new possibilities in the shape of quantum computing, with processors that could work millions of times faster than the ones we use today.
The key features of an ordinary computer—bits, registers, logic gates, algorithms, and so on—have analogous features. In a quantum computer instead of bits, a quantum computer has quantum bits or qubits, which work in a particularly intriguing way. Where a bit can store either a zero or a 1, a qubit can store a zero, a one, both zero and one, or an infinite number of values in between—and be in multiple states (store multiple values) at the same time! Just as a quantum computer can store multiple numbers at once, so it can process them simultaneously. Instead of working in serial (doing a series of things one at a time in a sequence), it can work in parallel (doing multiple things at the same time). Only when you try to find out what state it's actually in at any given moment (by measuring it, in other words) does it "collapse" into one of its possible states—and that gives you the answer to your problem. Some estimates suggest a quantum computer's ability to work in parallel would make it millions of times faster than any conventional computer.
Sounds amazing, but the trouble is that quantum computing is hugely more complex than traditional computing and operates in the Alice in Wonderland world of quantum physics, where the "classical," sensible, everyday laws of physics no longer apply.
As Richard P. Feynman, one of the greatest physicists of the 20th century, once put it: "Things on a very small scale behave like nothing you have any direct experience about... or like anything that you have ever seen."
In reality, qubits would have to be stored by atoms, ions (atoms with too many or too few electrons) or even smaller things such as electrons and photons (energy packets), so a quantum computer would be almost like a table-top version of the kind of particle physics experiments they do at CERN! You wouldn't quite be racing particles round giant loops and smashing them together, but it would need mechanisms for containing atoms, ions, or subatomic particles, for putting them into certain states (so you can store information), knocking them into other states (so you can make them process information), and figuring out what their states are after particular operations have been performed.
Apparently a quantum computer is great for 3 problems:
Machine Learning
Now, it's all well and good understanding what a quantum computer is and how (to an extent) it works but what can it, potentially do...
Google and NASA found that a quantum computer system with 1,097 qubits outperformed existing supercomputers by more than 3,600 times (and personal computers by 100 million x) on an optimization problem, solving it in mere seconds!
By simultaneously processing all combinations of inputs in a massively parallel fashion, and by taking advantage of a property dubbed “quantum tunneling,” quantum computing can tackle extraordinarily complex data challenges.
Quantum computers will change data security. Even though quantum computers would be able to crack many of today’s encryption techniques, predictions are that they would create hack-proof replacements.
There are several algorithms already developed for quantum computers including Grover’s for searching an unstructured database and Shor’s for factoring large numbers.
I've done a fair bit of research and reading around what they can do, so I think I can safely say, at this moment in time, nobody really knows. However I've drawn some conclusions which I would like to share with you. Firstly, for now, I think we can assume that we're not going to have quantum computers in our home any time soon, they need exact temperature and stability, and of course you don't need a quantum computer to online shop or send an email. Also they are going to need programming, choosing your UI or background is not going to be an option. In fact let's remove the word 'computer' and replace with:
"Machines That Can Solve So Many Problems We Don't Even Know We Need to Solve Yet and Do Lots Of Other Stuff That We're Just Not Sure About"
I've spent a fair bit of time researching this article, always happy to hear your thoughts/emotions!
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Kesia Coggs-Groom
Talent Acquisition Specialist - Other