Using new laser techniques, scientists can cool a matter to the coldest known temperature, less than a millionth of a degree above absolute zero.
Tonight, William Phillips, whose laser cooling and trapping research made him co-winner of the 1997 Nobel Prize in physics along with Stevena Chu and Claude Cohen-Tannoudji, will present “Almost Absolute Zero: The Story of Laser Cooling and Trapping” at the Phyllis P. Marshall Center Ballroom at 7 p.m. Phillips will demonstrate how lasers are used to cool atoms and will also discuss some of the newest developments in physics.
During the lecture, which is open to the public, Phillips will discuss cutting-edge technology, said Pritish Mukherjee, chairman of the USF department of physics.
Absolute zero is the temperature at which atoms cease all motion, said Mukherjee. On the Fahrenheit scale, that is 459 degrees below zero.
“The laws of thermodynamics and quantum mechanics both imply that absolute zero is not attainable. However, physicists are trying to get as close to it as possible,” Mukherjee said.
According to Mukherjee, laser cooling works by slowing the movement of an atom. The stream of photons making up laser light is directed at the atoms. The photons bounce off of them, slowing the movement of the atoms and allowing scientists to cool matter to temperatures lower than ever before.
Laser cooling has been used in such devices as atomic clocks and could lead the way to smaller electronic chips.
“Dr. Phillips’ group is working on using this for nanolithography, which would have direct application in miniaturizing electronic circuits,” Mukherjee said. “Lithography is the technique by which you try to write lines — for example, for electronic circuits.”
Laser-cooled atoms may lead the way to techniques that would allow scientists to draw much finer lines than they are able to draw now.
“This means a higher density of components on a chip, which means reduction of chip sizes,” Mukherjee said.
Phillips’ visit is part of a lecture series in the College of Arts and Sciences’ Nobel Laureate in Science. February 2003 brought Horst Stormer, professor of physics at Columbia University and recipient of the 1998 Nobel Prize in physics, to the campus presenting “Small Wonders: The World of Nano-Science.”
Phillips will also present a seminar called “De Broglie Wave Optics with Laser-Like Atoms” on Friday at 4 p.m. in the physics department auditorium. Mukherjee added that at this seminar, also open to the public, Phillips will present a more in-depth look at the application of laser cooling techniques.
“What de Broglie suggested was you could take the same mathematical relations that describe the energy and the frequency of light, and apply it to matter,” Mukherjee said. “He hypothesized that matter, just like light, could, under appropriate conditions, exhibit wave-like properties.”
Scientists have been able to observe these properties in laser-cooled atoms.
“It might be a harbinger of things that are to come,” he said. “Who would have guessed 30 years ago that lasers that had just been discovered in the 1960s would become a routine part of our lives as barcode scanners in grocery stores? When you find out something new and innovative, humans are resourceful enough to find creative uses for it.”