7 reasons to get excited about the future of quantum computing

25 July 2017

Computers have revolutionised the way we work, play and communicate - and just as they changed the world we live in, so will quantum computers (but perhaps even more so). 

Technology is evolving at a pace that that most of us can’t keep up with. The second we buy a new phone, better features are being developed that make our existing product seem out of date.

Computers are no different, technology is continually improving with each model but the research that’s being done now is unprecedented.  Quantum computing advancements are likely to be as revolutionary as the 1957 discovery of the first programming language (FORTRAN) that made digital computers mainstream. But forget the idea that computers are only those that sit on your desk helping with your study. We’re talking advancements to the types of computers that are within almost every piece of technology from your car and your air conditioner to medical machinery and aircrafts.

And the best part is we’re closer than ever to being able to build a tangible product thanks to the efforts of Station Q Sydney – a multi-year partnership between Microsoft and the University of Sydney.

The collaboration gives an unprecedented opportunity for our students to work alongside Microsoft’s most talented employees in their research of world-changing technology. Headed up by scientific director Professor David Reilly, staff and students will work in purpose built laboratories and cleanrooms for nanofabrication and quantum science right here on campus. 

So what capabilities could quantum computers offer that their existing counterparts can’t? We visited the Quantum Nanoscience Laboratory to talk to the students and researchers working on the project to find out.

A big motivator for building the transistor was for hearing aids, and applications like complete libraries on a flash drive or cat gifs on twitter were undreamed of. With this in mind, I think the most revolutionary use for a quantum computer will be something we haven't thought of, and something that will emerge once the machines grow.

PhD candidate Alice Mahoney

Alice Mahoney, a PhD candidate from the School of Physics, starts off by addressing the fundamentals of current computer technology.

“We know that by shuttling charged particles (specifically, flows of electrons) back and forth in a transistor, scientists and engineers have been able to create the sophisticated computers that we have today.”

Computers contain millions of transistors that together create a logic gate which is used by the computer to make basic decisions. This is made possible as each transistor acts as a switch. They can either be switched on or off to give a reading of 0 or 1 allowing the computer to determine an outcome. 

But transistors can’t solve every problem we have because these switches can only be in one state at one time (zero or one). Dr John Hornibrook a University of Sydney PhD graduate turned Microsoft employee elaborates. “The problems a conventional computer can solve are limited by the physics of how a transistor works.”

“A quantum computer is different because the basic building block is quantum mechanical. So whereas a transistor machine is limited by a particular rule set, a quantum computer can exploit phenomena such as entanglement and superposition to operate in a new way with a new fundamental building block and new logic gates.”

What is superposition you say? It’s the quantum principle that states particles are able to take on multiple states at the same time, and it’s this property that means quantum computers could do things much more quickly than existing ones as they can solve many problems concurrently.

“By exploiting the quantum-ness of isolated particles, we can open up a whole new way of storing, transferring, and processing information”, adds Alice.

And the complexity of the problem quantum computers can solve is also likely greater according to John.

“Theorists have already come up with algorithms even without a physical machine that will efficiently solve problems that are presently intractable for conventional computers,” he says.

PhD graduate John Hornibrook

To make things a little clearer, imagine you were given a lock you had to decode and there were hundreds of possible combinations. On your own cracking the lock would take quite a long time, but now consider if you were able to do different things all at once, you could concurrently apply many different combinations and you would achieve your mission much faster. This is exactly how scientists believe quantum computers will surpass conventional ones using quantum mechanics.

These quantum advancements could have several impressive applications for our society including more accurate weather predications, improved commute times, safer aeronautical systems, better identification of planets and life, self-driving cars, improved drug treatments and hyper-personalised marketing.

Consider your commute time. You currently rely on a computer to calculate your best method of transport, but a quantum solution could calculate all possible travel options and routes simultaneously taking into consideration conditions and spit out a result almost instantaneously. (This could also be applied in an aircraft traffic control situation, saving you from circling the airport or queuing on the tarmac.)

Similarly, in medical science the process of testing how a drug reacts with a cell takes thousands of attempts, but what if this could all happen at the same time? We’d discover better drug treatments much more rapidly. And so you can see, quantum computing could save us quite a lot of time – more than a lifetime in some cases.

Alice believes that though the path ahead is certainly unchartered, it’s definitely worthwhile.  

“Foreseeing the possible applications of a quantum computer are very tricky. There are glimpses here and there of how powerful these machines could be, so it will be exciting to see just how far this technology could take us.”

John does conclude that many of these applications are highly speculative but does acknowledge that some abilities have already been proven.

“There are some concrete algorithms that have already been developed in advance of the hardware. A commonly used example is Shor's algorithm to factorise a number into two primes. This seems banal; however this underpins a lot of currently used cryptography schemes. Another promising use is using a quantum computer as a quantum physics simulator. This should offer insights for a variety of problems – energy and drug development come to mind – and a better understanding of physics as well.”

Interestingly it’s the things we can’t imagine that most entices Hornibrook about the future of quantum computing.

“A big motivator for building the transistor was for hearing aids, and applications like complete libraries on a flash drive or cat gifs on twitter were undreamed of. With this in mind, I think the most revolutionary use for a quantum computer will be something we haven't thought of, and something that will emerge once the machines grow,” he says.

So how long do we have to wait before we’re immersed in a whole new world of technology? John holds his cards close to his chest.

“There's a joke that quantum computers are always 15 years away. So, I guess 15 years, although there's every reason to think that some problems will be tackled earlier.”

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