Quantum computers are expected to be lean, mean problem-solving machines

We use computers in just about every facet of our lives. Most of us carry tiny computers around in our pockets and, with a simple tap, can pay for our groceries, access locked buildings or send a message to the other side of the world.

Then there are the uses that have become central to our economies and societies, not to mention our personal lives – in some cases, literally: medical technology, banking, rail systems, traffic control, supply chains. The list goes on. Our demands are becoming increasingly complex and multi-faceted.

The solution is simple. We need to go quantum.

Quantum computing that is. Which is not, in fact, simple at all.

Lindsay LeBlanc

Lindsay LeBlanc

Robert Wolkow

Robert Wolkow

Ray Decorby

Ray Decorby


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“It’s not just that quantum computing is faster. It’s actually different,” says Lindsay LeBlanc, Canada Research Chair in Ultracold Gases for Quantum Simulation.

Scientists see this yet-to-be-realized technology as the key to cracking many intractable problems and a possible solution to the world’s insatiable need for computing power. Researchers like LeBlanc and others at the University of Alberta are among those striving to make the technology viable.

“The world’s computers are grinding away and using a huge amount of energy,” says Robert Wolkow, a U of A expert in nanoscale information and communications technology. “It’s totally unsustainable. We need more efficient computers.”

In addition to quantum computing, two other quantum technologies are at the forefront of research.

Quantum sensing measures physical quantities such as electric and magnetic fields, chemical processes and temperature with tremendous accuracy and precision. It promises to give us new insight into what’s in our bodies, in the ground and all around us.

Quantum communication makes many of today’s high-tech options seem like relics, providing greater degrees of security than we’ve ever imagined. Innovations in this sphere could help keep our data safe in everything from health care to banking.

So what is quantum computing?

One of the key differences between quantum and regular computers is how they store information. Regular computing uses binary digits, a.k.a. bits, where each bit stores one piece of information: either a zero or a one. Quantum computing uses quantum bits, called qubits [kyoo-bits]. Thanks to a quantum property called superposition, qubits level up the standard binary code. Rather than being either zero or one, they can be both at the same time.

“There are two pieces of information carried with that one physical object,” explains LeBlanc. “That’s really at the heart of why it’s so much more powerful.”

Quantum computers are expected to be lean, mean problem-solving machines. Their unique properties mean they could tackle questions and calculations that regular computers would find prohibitively challenging because the property of superposition (the same one that allows each qubit to store more information) allows quantum computers to analyze many things simultaneously.

They are expected to excel at two key types of problems, LeBlanc explains.

The first has to do with optimization, where a computer program tries to figure out the best path to do something when there are many options. The world presents countless real-world optimization problems: planning the most efficient route for a delivery person with multiple packages and stops, for example, or helping health researchers find the one chemical or molecule they need amid a sea of options.

Quantum computers are also expected to outdo today’s computers when it comes to security because of an intriguing quantum property called the no-cloning theorem. With information stored in qubits, explains LeBlanc, “you can’t look at it and make a direct copy of the information without destroying it.” This means that the user will know immediately if a quantum computer is hacked and be able to avoid the loss of sensitive data.

So how do you make a quantum computer? The components aren’t whipped up in the machine shop or factory. It takes atoms to make them run. And atoms need to be contained in order to work with them.

Engineering professor Ray Decorby works on what’s called “cavity quantum electrodynamics,” which involves taking fundamental particles such as atoms and confining them in tiny containers.

“Once confined, we can make them interact in a way that can be controlled at the quantum level and can be useful for performing quantum functions,” says Decorby.

Working at the quantum level also requires cooling the atoms to incredibly cold temperatures, around -273 degrees Celsius. This minimizes the chances of qubits moving from one energy state to another in an unpredictable way. At warmer temperatures, LeBlanc explains, “you don’t have that control over setting your qubit. It gets scrambled up because it vibrates more as the temperature increases.”

When atoms are ultracold, their movement slows down. As a result, they begin to act together, with their behaviour governed by quantum mechanics. “They’re a very nice test bed for quantum technology,” says LeBlanc, whose area of expertise is ultracold research.

LeBlanc estimates that the widespread use of quantum computers could come within a decade. They’ll likely be housed in large research facilities at universities and corporations – much like when regular computers were mammoth machines that took up entire rooms. They’re most likely to be accessible to the rest of us, at least initially, as a remote cloud service.

The research race is already on to create systems with more and more qubits. As little as two years ago, it was common to see 50-qubit prototypes, says LeBlanc. That has since increased to 100-qubit systems. The more qubits a system has, the more problems and the greater complexity it can handle.

A lot of research has to take place before quantum computers become an everyday fact in our lives, LeBlanc says, but the fact that the technology is moving from the lab to the real world is already a big win in her eyes.

“It’s a fundamental principle of our universe, that it is quantum and it works this way,” says LeBlanc. “If we can actually harness that, it’s a really powerful thing.”

| By Adrianna MacPherson

This article was submitted by the University of Alberta’s Folio online magazine, a Troy Media Editorial Content Provider Partner.

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