Small world

Small world

Theoretical physicists at McMaster University are studying the smallest of sub-atomic particles in hopes of making big changes in the way we live
March 1, 2005
Just when we thought scientists had explained the world ten times over, they find a new way to explain it some more.
 

This time quantum theorists—those scientists who study quantum physics—are taking their turn. They’re probing the world of small electrons—the small particles that make up the matter that exists in almost everything around us—and developing new theories to explain the mechanics behind the most common elements.

One of those scientists working on new theories is Dr. Catherine Kallin, Professor of Physics and Astronomy at McMaster University. As a leading-edge condensed-matter physicist, her research aims to better understand how our world works by studying how materials such as magnets and superconductors are made.

“The focus of my research is to find novel properties in new materials and to develop an understanding for new types of devices and applications far down the road,” says Kallin. “I’m interested in the whole range of exotic things that can happen.”

Part of Kallin’s research involves working with superconductors. If you put too much electricity through a wire, it heats up and can even burn. But superconductors carry very large currents without heating.

One current use of superconductors is for magnetic resonance imaging (MRI) machines in hospitals. Another use involves high-speed MagLev trains, such as those used in Japan. These trains, and the rails they travel along, have the novel property of expelling magnetic fields. The science behind it is called the Meissner Effect and it enables the train to float above the rail, cutting down on friction and drag and allowing travelers to reach their destination in record time—at about 550 kilometres per hour.

Superconductors have a long history. Conventional superconductors were discovered in 1911, while high-temperature superconductors were discovered in 1986. However, there are still many unanswered questions about the use and behaviour of both. For over 14 years, Kallin and her colleagues have been trying to determine how to understand and explain this behaviour. “What are the underlying physical mechanisms that cause high-temperature superconductivity? That’s what we’re working on,” says John Berlinsky, Chair, Department of Physics and Astronomy at McMaster University.

It’s one thing to use superconductors for trains here on terra firma, but what about using them in outer space? Berlinsky says that just as superconductors can improve the reception of electrical currents for electricity on earth, they can do the same for communication technology orbiting the earth.

Benefits

Theoretical physicists help us understand the properties of new materials, which are the ingredients of future technology. Using efficient superconductors in electrical generating plants could provide a more reliable source of electricity with better delivery, creating less pollution.

If physicists and chemists are able to push the temperature boundaries of superconducting even further, life as we know it would be quite different. “If we can get it towards room temperature (around 20 degrees Celsius), that’s where it would change technology,” says Catherine Kallin. “We could transport energy from one place to another at a very low cost, and with practically no waste.” Kallin explains that by transmitting power from one location to another (such as from the location where the power is generated to your home) energy is lost due to electrical resistance in the cables. However, if the power is transmitted through superconducting cables, there is zero electrical resistance and no energy is lost. This means substantial savings.

Superconductors are also changing microwave communication technology such as those used in cell phones and satellites. “There’s no electrical loss and the signals are sharp,” says John Berlinsky. “The trick has to do with how many frequencies you can use at the same time because it determines how much information you can pack into your signals. It’s ultimately the difference between a few hundred calls on one circuit and many thousands.”

Superconductors could also potentially change the conventional computer. A typical computer stores information using binary code, a series of zeros and ones. But there are storage limitations to binary systems. Quantum computers, however, are much more more flexible in storing information.

Partners

The Canadian Institute for Advanced Research (CIFAR) makes science exploration possible. Providing grants for scientists, the privately and government funded organization, among many things, enables scientists to take time out from teaching to pursue their research. “The CIAR also helps to foster a community of researchers,” says Kallin. “Because Canada is so sparsely populated and our researchers are spread all over, the CIAR helps bring us together to discuss our work.”

In Cambridge, Ontario, COM DEV is making leaps and bounds using superconducting technology in the commercial sector. COM DEV manufactures and designs scientific instruments and satellite links. Currently, COM DEV has 85 different patents for this type of technology. During Kallin’s work with Materials and Manufacturing Ontario, COM DEV partially funded her research.

Learn More

View “From Superconductors to the Theory of Everything: A Journey Through the Physics of Electrons”, presented by Profesor Kallin as part of a lecture series at the Aspen Centre for Physics, Aspen Colorado, 2003.