Prof. George Sawatzky says UBC physicists are helping develop quantum materials that will usher in the next generation of information technology.
The silicon semiconductor circuits at the heart of your computer rely on physics developed in the 1940s and 50s. But we are reaching the limits of what they can do.
Fortunately, physicists and chemists have discovered a raft of new materials to explore. These so-called quantum materials, often compounds of oxygen and metals with other elements thrown in for good measure, will drive the future.
UBC Physics Professor George Sawatzky says devices based on combinations of quantum materials are full of promise. A single chip, for example, could measure insulin in a patient’s blood, process the data it gets, store the information, and communicate with other devices. Another chip could act as a camera that can fit in a retina and interface with optical nerves.
“You have so much more richness in possibility with quantum materials,” Sawatzky says. “They can do just about everything.”
Interfaces a key to understanding
Taking advantage of these quantum materials requires they be better understood. This is where UBC is hoping to leverage its existing expertise in creating and characterizing these new materials.
“Worldwide, we are in the upper echelon” in this area, says Prof. Jeff Young, director of the Advanced Materials Processing and Engineering Lab (AMPEL), where much of the department’s work in quantum materials happens.
The Physics department, UBC, and the federal government are teaming up for a major push in quantum materials. UBC recently became home to a Canada Excellence Research Chair in this area, with $10 million in funding over seven years. UBC is adding another $30 million to this research program.
New tools in the quantum toolbox
Quantum materials are not just for miniaturizing what we can already do. Once you open up the quantum toolbox, just about anything is possible. Professors Young and Josh Folk, for example, are using interfaces in quantum materials to look at something called spin currents, analogous to electrical currents.
Unlike electrical currents, spin currents don’t take any energy to maintain, and don’t have any limits on how fast they can be changed. Computers based on spin would be faster and use less energy—and they would never “turn off,” eliminating the drag of boot up and shut down.
Researchers are imagining other approaches, in which circuits take advantage of the flexibility of quantum materials to make computer elements that can be more than just “on” or “off.”
These approaches would be a better fit for the kind of fuzzy logic and natural language processing so powerfully displayed by Watson, the IBM computer that beat two Jeopardy champions in 2011. Pairing that type of software with more suitable hardware could push computers to the edge of consciousness—and beyond.
We’re not there yet
Challenges remain in bringing quantum material interfaces to practical application. Unlike semiconductors, which are described by a single theory, quantum materials are currently understood thanks to a patchwork of theories, each of which applies to a different substance. In order to predict what happens at an interface, where two different materials come together, these theories need to be brought under a single framework. That is “still very much in the beginning,” according to Sawatzky.
Better control in fabricating the interfaces is needed as well. A semiconductor transistor can have a transition region a millionth of a metre wide; this sounds small, but it’s ten thousand times larger than the single atom precision that many interfaces in quantum materials need in order to realize their unique properties.
Difficult challenges, to be sure. Yet the scientists at UBC are almost giddy at what the future holds for the physics department. With the resources being marshalled and the expertise in place, UBC is poised to be at the centre of the next information revolution.
“If anyone can do it, we can,” says Sawatzky.