Q&A: Talking quantum computing with SFU physicist Stephanie Simmons

November 28, 2016

By Allen Tung

Tiny silicon transistors are the essential building blocks of most modern electronics, powering the computer chips and processors inside our phones and computers.

Silicon may again be the key to an entirely new technological revolution as scientists race to overcome the boundaries of quantum mechanics, which prevent us from shrinking silicon transistors any further without making them inoperable.

While some scientists seek an alternative to the silicon transistor in their bid to build computers with ever greater processing power, SFU physics professor  Stephanie Simmons begs to differ. She says harnessing quantum mechanics rather than avoiding it will make the so-called quantum computer a reality.

She will share her research on Wednesday, Nov. 30 at SFU’s Vancouver campus in Harbour Centre room 1400 as the next speaker in the annual SFU President’s Faculty Lecture Series.

In anticipation of her lecture, Simmons, a Tier II Canada Research Chair in Quantum Nanoelectronics, answers a few questions from SFU News about quantum computing and her research:

Can you explain, as if I’m 12 years old, what quantum computing is?

Quantum computing is the attempt to harness the laws of quantum mechanics to build incredibly powerful computers that can perform some incredibly demanding computational tasks: tasks so demanding that they would otherwise take the age of the universe to perform.

No matter how good or “fast” today’s computers have become, they’re limited by the laws of physics on how data is stored and processed. After all, all information is ultimately physical, and is stored and processed according to the laws of physics.

At “large” scales, so-called “classical” physical laws dominate the behaviour of objects just as you would expect. For example, you can flick a physical switch from off (‘0’) to on (‘1’). However, at the atomic scale, or when certain objects are very cold, the laws of quantum mechanics dominate over classical physical laws.

One particularly powerful law in quantum mechanics allows objects to be in two configurations at the same time—like two distinct places at once. Currently, a bit of data can only be either a ‘0’ or a ‘1’ but a quantum bit—or a qubit—can be both a ‘0’ and ‘1’ at the same time.

So, are you building a quantum computer at SFU?

Yes. The Silicon Quantum Technology research group, which I lead, is focussed on building quantum computing hardware using silicon. This is the same material that modern transistors, which power most electronics, are made from.

Silicon crystals are among the few physical objects that have truly excellent quantum properties. Hopefully, they will eventually support full-fledged quantum technologies and computers.

How close are we to building a quantum computer?

Realistically, we’re still a long way away from building a quantum computer, but the goal now seems convincingly within reach. Big industry players such as IBM, Google, Intel and Microsoft are now in the game, racing alongside academia. The pace of progress in this field is rapidly accelerating.

Right here at SFU, researchers broke a number of world records in 2013 for quantum “lifetimes” and some of these records still stand today. Quantum bits have an inherent “lifetime” in that they can only be ‘0’ and ‘1’ at the same time for a certain window of time.  We’re now working to assemble networks of these quantum bits to create progressively larger quantum processors at my lab.

There is a big push in the field to be the first to unlock the considerable power of quantum technologies.

If scientists were to build a quantum computer within the next decade, what could  we expect?

Even though a prototype quantum computer doesn’t yet exist, we already know there are a few critical tasks where quantum computers will dramatically outperform modern supercomputers. Examples include chemical simulations to design better drugs, improved big-data search capabilities and algorithms, and the design of materials to make, for example, higher capacity batteries for clean technologies. It also opens up the possibility for other quantum technologies such as provably unhackable quantum encryption and quantum sensors.

Neato. How can I learn more about quantum computing?

I’m the next speaker in the annual SFU President’s Faculty Lecture Series. The event takes place on Wednesday, Nov. 30 at SFU’s Vancouver campus in Harbour Centre, room 1400. This free event, hosted by SFU Public Square, begins at 7 p.m. and interested attendees should RSVP.

My talk will not assume any familiarity with quantum mechanics. I’ll explain the basics of how a quantum computer will work, and what gives them their incredible power. I’ll also give a brief overview of where we are in this race to build a quantum computer, and why I think it’s worth betting that silicon will once again revolutionize the information age.

A whole new technological revolution is coming—and incredibly, we can already get a sneak peek into just how much it is going to change the world.