Winners

2007 NSERC John C. Polanyi Award

Two Canadian researchers have caused a revolution in molecular science by developing most of the main concepts of a new field known as "attosecond science." Attosecond science fuses chemistry and physics to arrive at the innovative idea of using intense, ultra-short laser pulses to image and even ultimately control molecules.

The achievements by André Bandrauk, Canada Research Chair in Computational Chemistry and Molecular Photonics at the Université de Sherbrooke, and Paul Corkum, Senior Scientist at the National Research Council's Steacie Institute and Adjunct Professor at the University of Ottawa have earned them this year's $250,000 John C. Polanyi Award from the Natural Sciences and Engineering Research Council of Canada (NSERC).

The researchers have combined the power of supercomputing and the latest laser technology to control and manipulate matter with lasers at the molecular level, both spatially and temporally. Their research could lead to advances in materials technology, bio-photonics and high-bandwidth telecommunications.

Drs. Bandrauk and Corkum are known for developing the science of molecules exposed to intense laser light and for exploiting this new science to generate and measure shorter light pulses and new methods for imaging and controlling molecules.

"John Polanyi's Nobel Prize-winning work on the emission of light during chemical reactions gave birth to a new concept, the chemical laser, wherein chemical energy could be transformed into coherent light, thus giving photochemists and photophysicists a new tool for enhancing chemical reactions of great importance to the chemical industry," Dr. Bandrauk said.

A theoretical chemist, Dr. Bandrauk began a productive collaboration in laser science with Dr. Corkum, an experimental physicist, in the mid-1980s. Their work over two decades has built on Dr. Polanyi's seminal work through Dr. Corkum's advanced laser experiments and Dr. Bandrauk's sophisticated state-of-the-art supercomputer simulations.

Their first work used chirped picosecond pulses, those with time varying frequencies to control molecular dissociation. Now, six orders of magnitude faster, they have shown that intense chirped attosecond pulses can monitor and control the electron and its complex quantum wave motion in matter, thus reflecting a major breakthrough in molecular science. An attosecond is a billionth of a billionth of a second – one thousand times faster than the femtosecond that was previously used as the measure for the shortest controlled light pulse. For example, an athlete winning a race by an attosecond would be ahead by less than the width of an atom.

Investigations of the inner workings of a molecule by taking atoms apart and putting them back together have led to a better understanding of the quantum nature of the smallest bits of matter in the universe. A conceptual new model was first introduced by Dr. Corkum and confirmed by joint theoretical and experimental collaboration. This allowed an electron to orbit and re-collide with an atom or molecule under the influence of an intense laser pulse, resulting in a revolutionary method that emits a light pulse faster than ever before.

"This research has led to major advances in understanding the interaction of matter with intense laser pulses leading to the generation of the shortest laser pulses to date, the attosecond pulse – the essential tool for controlling electrons in matter," Dr. Bandrauk said. "This will lead to a revolution in science since it is expected the attosecond pulse will become the preferred tool for controlling matter with important ramifications for the photonics industry to come."

Attosecond pulses open up new avenues for time-domain studies and control of multi-electron dynamics in atoms, molecules, plasmas and solids on their natural, quantum mechanical time scale and at dimensions shorter than molecular and even atomic scales. These capabilities promise to change the understanding of matter where the quantum wave nature of matter dominates.

Previously, chemists thought that intense light pulses would destroy molecules rather than producing interesting science. Dr. Bandrauk showed, through theory and supercomputer modelling, that new molecules could be created with intense short laser pulses. The original investigation by the two researchers of the nonlinear, nonperturbative reaction of atoms and molecules to intense laser pulses resulted in the major discovery of the generation of attosecond pulses.

"We have shown how this new technology can be used to image molecular structure and its temporal evolution," Dr. Corkum noted. "Both Science and Nature, two of the most important science journals worldwide, highlighted the development of attosecond pulses as one of the 10 most important advances in all science in 2002."

As well, The Economist reported last year that attosecond science has brought the world's scientific community into "an era of control of the quantum world." It said further: "If such processes (electronic) could be manipulated, then it would have applications in fields as far apart as computing and medicine."

That is the next challenge for the researchers: the application of attosecond pulses to controlling electrons inside molecules.

These advances in visualizing, understanding and ultimately controlling the wave nature of one of the most mysterious objects in science – the electron itself – have put the Bandrauk-Corkum group of researchers at the forefront of this new area of science. It also highlights Canada's eminence in a new field of research that can be referred to as "dynamic imaging."

The NSERC John C. Polanyi Award will enable Drs. Bandrauk and Corkum to further their study of a field in which Canada is an acknowledged leader.