Daniel Tsui of Princeton won the 1998 Nobel Prize in Physics
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Daniel Tsui of Princeton, Horst Stormer of Columbia University, and
Robert Laughlin of Stanford won the 1998 Nobel Prize in Physics "for
their discovery of a new form of quantum fluid with fractionally
charged excitations," according to the Royal Swedish Academy, which
announced the prize Tuesday morning in Stockholm.

Daniel Chee Tsui, 59, was born in Henan, China, in 1939. He went to
"Pui-Cheng" High School in Hong Kong. He came to the United States in
1958 to attend Augustana College in Rock Island, Ill., and graduated
Phi Beta Kappa. He received his doctorate in physics from the
University of Chicago and was appointed a professor at Princeton in
1982.

OCPA and its members would like to extend our heartiest
congratulations to Professor Tsui for winning the Nobel Prize in
physics, which is the highest honor a physicist can achieved. We also
wish him many more great successes and continuing contributions to
physics in the future.

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The following is the news release from Princeton University
in http://www.princeton.edu/pr/home/hmcap.html

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Princeton, N.J. -- Daniel Chee Tsui, Arthur Legrand Doty
Professor of Electrical Engineering, on Tuesday has won the 1998 Nobel
Prize in Physics for his 1982 discovery with co-winner Horst
L. Stormer, now of Columbia University, of the fractional quantum Hall
effect. A third co-winner, Robert B. Laughlin, explained their result
the following year. The experiments by Tsui and Stormer led to
Laughlin's finding that the electrons in a powerful magnetic field can
form a quantum fluid, in which "parts" of an electron can be
identified.

Tsui's work stems from a 1879 finding by a student, Edwin H. Hall, who
discovered a pattern in the flow of electric current when a gold plate
is placed in a magnetic field at right angles to its surface. The
current flowing along the plate would drop at right angles. This
phenomenon, termed the Hall effect, can be used to determine the
density of charge carriers in conductors and semi-conductors and is a
standard tool in physics laboratories.

In Hall's day, such experiments were performed at room temperature
with moderate magnetic fields. By the 1970s, researchers could perform
experiments at extremely low temperatures, with very powerful magnetic
fields. The 1980 experiment by Klaus von Klitzing found that the Hall
effect in the semiconductor silicon does not behave in a linear
fashion, but instead creates "steps" along the strength of the
magnetic field (von Klitzig won the 1985 Nobel Prize for this
discovery).

Tsui and Stormer, then at Bell Laboratories in Murray Hill, New
Jersey, performed experiments on the quantum Hall effect in the
semiconductor gallium arsenide, using even lower temperatures and more
powerful magnetic fields. To do so, they created a unique environment,
a trap in which to restrain electrons on a two-dimensional plane. This
was done by sandwiching two dissimilar semiconductor wafers--gallium
arsenide on one side and gallium aluminum arsenide on the
other. Electrons accumulated at the interface between the two
semiconductors and were tightly confined. Next, the researchers cooled
the electron trap down to a tenth of a degree above absolute zero.

To their surprise, Tsui and Stormer found that the next step in the
Hall resistance was three times higher than von Klitzing's highest
recorded step. Later, Tsui and Stormer found more steps, which
initially could not be explained. The heights of the new steps could
be expressed with the same constant used in earlier work, but were now
divided by different fractions -- thus, the term fractional quantum
Hall effect. This would be impossible, since electrons cannot have
fractional charges. Laughlin later determined that the magnetic field
had created "holes" in the two-dimensional sheet of electrons. Called
vortices, these were similar to a whirlpool in a lake; in the absence
of water, the vortices represent an absence of charge.

The discovery of apparently fractional electron charge opened a new
era in the study of many-body phenomena. It has had impact on many
branches of physics. Researchers around the world continue to make new
discoveries that spring from the fractional quantum Hall effect.

Born in Henan, China, in 1939, Tsui came to the United States in 1958
to enter Augustana College, Rock Island, Illinois, from which he
graduated with Phi Beta Kappa honors in 1961. After earning his
Ph.D. in physics at the University of Chicago in 1967, Tsui did a year
of postdoctoral research at Chicago before joining Bell Labs in 1968.

Tsui joined the Princeton faculty in 1982. His is an elected member of
the National Academy of Sciences, a fellow of the American Association
for the Advancement of Sciences, a fellow in the American Physical
Society, and a recipient of the 1984 Oliver Buckley Condensed Matter
Physics Prize of the American Physical Society. Earlier this year, he
was honored with the Benjamin Franklin Medal in Physics.

Tsui lives in Princeton with his wife, Linda. He is the 29th winner of
the Nobel Prize associated with Princeton University, and the 18th
person affiliated with Princeton to win the prize in physics.

More information is available at the Royal Swedish Academy of Sciences

Daniel C. Tsui biography

Picture of Daniel C. Tsui

Computer graphic visualizing the Laughlin wave function for the nu=1/3
FQHE state.

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