Modes in Random Media Azriel Z. Genack, CUNY Queens College, DMR 0907285

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Modes in Random MediaAzriel Z. Genack, CUNY
Queens College, DMR 0907285
The state of a quantum or classical system is a
superposition of resonances, also called modes.
An intuitive understanding of random system can
be gained from considering the underlying modes
of the medium. But a systematic modal approach
has not been possible because there were no
experimental observations. We have succeeded in
decomposing the field in random speckle patterns
of transmitted microwave radiation into a sum of
patterns of the modes of the medium, even when
they overlap spectrally. This allows us to
explain complexities of steady state and pulsed
transmission of localized waves in terms of the
surprisingly strong correlation in the speckle
patterns of adjacent modes. The transmission of
individual modes and the intensity speckle
patterns of two adjacent mode are shown on the
right.
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Modes in Random MediaAzriel Z. Genack, CUNY
Queens College, DMR 0907285
Three high school students, three undergraduates
one masters student are learning the basics of
research in our lab this year. One of the
undergraduate, Yitzchak Lockerman, has published
two papers, submitted a third and is preparing a
fourth of which he will be first author. In that
work, he has shown that points of vanishing
intensity in the transmitted intensity speckle
diffuse as the frequency is scanned. Yitzchak was
awarded a National Goldwater Scholarship this
year and will begin graduate studies in computer
science at Yale this Fall. One gradate student,
Jongchul Park, who has just received his Ph.D,,
has found the universal statistics in all
dimensions beyond 1D. A figure from his research,
appeared on the cover of the review volume seen
on the left. Another student, Jing Wang, has
decomposed randomly scattered microwave radiation
into the underlying modes of oscillation, while a
third student, Zhou Shi, has found the
eigenchannels of the transmission. This has made
it possible to pass nearly 100 of a waves
energy through a strongly scattering system in
which only a few percent of the wave energy is
typically transmitted. A picture of some members
of our group is shown on the left.