Hau, Lene Vestergaard

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Lene Vestergaard Hau

Physicist

Born November 13, 1959, in Vejle, Denmark. Education: Received B.S. and M.S. degrees from the University of Aarhus, and Ph.D., 1991.

Addresses: Office—Rowland Institute for Science, 100 Edwin H. Land Blvd., Cambridge, MA 02142.

Career

Postdoctoral fellow in physics, Harvard University, 1989-91; scientific staff member, Rowland Institute for Science, 1991—; Gordon McKay professor of applied physics and professor of physics, Harvard University, 1999—.

Awards: MacArthur Fellowship, John D. and Catherine T. MacArthur Foundation, 2001-06.

Sidelights

Danish physicist Lene Vestergaard Hau entered the annals of science history in 2001 when she and her team of researchers at Harvard University became the first to physically halt the speed of light. Later that year, Hau was awarded one of the MacArthur Foundation "genius" grants for her accomplishment. For a researcher whose proposal was once rejected for funding by the National Science Foundation because she had little practical experience in the experiments she was planning, the $500, 000 MacArthur prize money was a welcome windfall. "If I discover a totally new area of research that I want to work in, " she remarked to Harvard Gazette writer William J. Cromie, "the fellowship gives me the funds to pursue it without being told that it's not my field."

Born in Vejle, Denmark, in 1959, Hau spent her college career at the University of Aarhus in her native country. She earned both undergraduate and master's degrees before moving to Cambridge, Massachusetts, to become a postdoctoral fellow in physics at Harvard University in 1989. The University of Aarhus would award her a Ph.D. two years later. Hau's area of interest was theoretical physics, but in Cambridge she became fascinated by the more experimental realm of physics. When the Rowland Institute for Science, which was affiliated with Harvard, hired her as a scientific staff member in 1991, she began to pursue her experimental work in earnest.

The Rowland Institute was founded in 1980 with a grant from Edwin H. Land, the inventor of Polaroid photography. Land wanted to create a working laboratory for experimental science research in the fields of physics, chemistry, and biology. Hau was particularly intrigued by what is known as the Bose-Einstein condensate. This was named for Albert Einstein, who first theorized it, and an Indian physicist, Satyendra Nath Bose, who correctly mapped out the theory. As Smithsonian writer John P. Wiley Jr. explained, "When you cool the right stuff down to a temperature of a few hundred billionths of a degree above absolute zero, strange things happen. The motion that animates every atom (in the macro world, we feel that motion as heat) nearly stops. This is the world of quantum mechanics, where classic physics no longer applies." Wiley continued, "The space in which each atom can be found spreads out farther and farther, overlapping with all the others. The atoms lose their identities, " and the cloud of them that forms is known in science as the Bose-Einstein condensate.

The first hint that Hau was working on a possible breakthrough in stopping the speed of light came in a 1999 issue of the journal Nature, when she described a successful experiment she conducted the year before. Scientists know that light travels through space at 186, 285 miles a second, a definition confirmed in 1926 by scientist Albert A. Michelson, the first American to win the Nobel Prize in his field. Scientists also knew that light could be slowed a bit if it encountered something transparent, like glass, which will refract the beam into the bent rays that the human eye sees as spectra, or the diffusion of color. By the same principle, Hau thought that the Bose-Einstein condensate could also be deployed in slowing the speed of light, because it has an unusually high refractive index.

In that 1998 project, Hau and her team managed to slow a beam of light down to just 38 miles an hour by shining it through a chamber filled with super-cooled sodium gas. They used a laser beam and spent one long 27-hour stint trying to achieve the intended result. Hau described the elation she and her fellow researchers experienced in an interview with Marisa Cohen in More. "When you realize that this is the first time in history anybody has seen light go this slow, " she enthused, "it's such an amazing moment, it's worth all the effort."

In 1999, Hau was appointed the Gordon McKay Professor of Applied Physics and Professor of Physics at Harvard. She was also given her own facility, known as the Hau Lab. There, she continued her experiments with slowing the speed of light even further, and had another breakthrough early in 2001, when she and the researchers actually stopped the beam of light completely. Another team of scientists, Ronald L. Walsworth and Mikhail D. Lukin of the Harvard-Smithsonian Center for Astrophysics, also announced the identical result, but noted that their own experiments had been based on Hau's initial findings published back in 1999. The Walsworth-Lukin group had not used sodium gas, but rather rubidium, an alkaline metal element.

New York Times science writer James Glanz explained the significance of both teams' work. "The achievement is a landmark feat that, by reining in nature's swiftest and most ethereal form of energy for the first time, could help realize what are now theoretical concepts for vastly increasing the speed of computers and the security of communications, " Glanz wrote. "Quantum computers could crank through certain operations vastly faster than existing machines; quantum communications could never be eavesdropped upon. For both these systems, light is needed to form large networks of computers. But those connections are difficult without temporary storage of light, a problem that the new work could help solve."

Hau was given one of the most sought-after honors in the world when the John D. and Catherine T. MacArthur Foundation named her as one of its newest "genius grant" recipients later in 2001. Formally known as a MacArthur Fellowship, there is no application process for the grant, and an anonymous committee decides who will receive the generous half-million-dollar stipend, which is parceled out in fifths over a five-year period. The winners, drawn from the arts and sciences, can spend the amount in any way they choose. Like nearly all the MacArthur genius-grant awardees, Hau first learned that she was under consideration when the surprise telephone call came to inform her that she had won. "I was totally stunned, " she admitted to Cromie in the Harvard Gazette. "I didn't have a clue."