Quantum Materials Research ProgressQuantum materials, and the insight gained from them, could contribute to powerful future technologies that will transform condensed matter physics, as well as day-to-day life. For instance, program members study “high-temperature superconductors,” materials that exhibit superconducting properties at much higher temperatures than that of other types of superconductor. Even these materials, though, must be cooled to more than -100°C.
The nature of high-temperature superconductivity has eluded physicists since its discovery more than 20 years ago. CIFAR researchers have made a series of recent breakthroughs in explaining the phenomenon, which have raised hopes of one day creating room-temperature superconductors – one of the “holy grails” of the Quantum Materials program. Eliminating the need to cool quantum materials could launch a scientific revolution, and also transform health care, environmental stewardship, public transit, and much more. Should these researchers succeed, MRI scanners could shrink from the size of a garden shed to the size of a laptop. Electricity grids could become vastly more efficient. High-speed “maglev trains,” which depend on superconductivity, would become vastly more affordable.
Program members approach problems like this from multiple perspectives, using a variety of materials. Much of the program research goes beyond superconductivity, but a great deal of the results sheds light on this specific enigma.
CIFAR researchers are leading the way to understanding of how properties such as superconductivity exist in circumstances that were previously thought to be physically impossible.
For instance, copper-based materials were long considered the only avenue for high-temperature superconductivity. Recently, though, high-temperature superconductivity was discovered in a totally different kind of material, based on iron. Many members of the Quantum Materials program are now collaborating to elucidate how electrons behave in these iron-based materials, with a view to finding the way to a room-temperature superconductor.
Two fruitful principles guiding the search for new states of electronic matter are to tune to a quantum phase transition – for example by suppressing magnetism with pressure – or to frustrate magnetic order – for example by placing electrons in a triangular environment.
So-called “cold atoms” offer another promising way to explore the mystery of how electrons self-organize to exhibit unusual and valuable properties. These atoms are found in gases that, when cooled to near absolute zero become superfluids – fluids that flow without friction. CIFAR researchers are working to find out whether other quantum states of matter can be created with cold atoms. Quantum gases, unique materials made of very cold gas atoms manipulated by laser light, are a new and important focus of the quantum materials research community. They allow researchers to study many of the unusual phenomena traditionally studied only in solid materials, but in entirely different and extreme conditions.
Another area of focus within the group is electron correlations at the interface between two different oxides. It turns out that the interface can have very different electronic properties, for example conducting electricity while the two oxides don’t. Researchers want to design interfaces with novel properties, enabling new technologies.
The strength of Quantum Materials research stems from its investigations into a variety of quantum systems. By linking theorists, experimentalists and materials scientists from around the world, they are well on their way to understanding the bizarre [remarkable?] quantum phenomena that, when harnessed, have the potential to transform our world.