Study Shows That Quantum Dots "Talk"
AEN News
Reno, NV - Scientists who hope to use quantum dots as the building blocks
for the next generation of computers have found a way to make these
artificial atoms communicate.
"Essentially, the dots talk to each other," said Ameenah Al-Ahmadi, an
Ohio University doctoral student who published the findings with Professor
of Physics Sergio Ulloa in a recent issue of the journal Applied Physics Letters.
The dots are tiny, engineered spherical crystals about 5 nanometers in
diameter. An average biological cell, in comparison, has a diameter
of about 1,000 nanometers. Researchers believe that quantum dots
will be extremely useful in developing nanoscale technologies
because they are versatile and uniform, which could eliminate
possible variations and flaws in materials.
In the recent study, the researchers were the first to use theoretical
models to show how light energy shining on quantum dots would prompt
them to transfer energy in a "coherent" fashion. They found that
when the dots were arranged a certain distance from each other
- greater than the radius of the dots - light waves traveled
between the nanocrystals in a consistent pattern. In previous
research, the light's wavelength would change or become irregular
during the energy exchange, which creates a breakdown in
communication between quantum dots.
The results suggest that there could be a way to transmit information
using light waves, laying the groundwork for a possible optical
quantum computer. In this device, light energy would replace the
electrical charge currently used to transfer information in
conventional computers.
"The idea is to make the (computing) process faster and smaller,"
said Al-Ahmadi.
The applications of the new quantum dot technology also could include
medical imaging. Quantum dots could be injected into the patient,
and a device containing more quantum dots could be used to show
the position of dots under the skin. Current biology research
has had great success with this type of imaging in mouse models,
Ulloa said. The dots have fewer side effects than contrast
chemicals used in X-rays, and may eventually replace traditional
contrast media.
Using light energy instead of electricity also would help keep
computer temperatures low, as the light energy does not create as
much heat as electrical current, Al-Ahmadi added.
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