Short-range scattering in quantum dots

Oct 20, 2010

Chinese researchers, reporting in the Journal of Applied Physics, published by the American Institute of Physics, have described a new breakthrough in understanding the way electrons travel around quantum dots. This might lead to promising new fabrication methods of novel quantum devices.

Guodong Li and colleagues at the National Center for Nanoscience and Technology in Beijing carried out an experiment using self-assembled and a two-dimensional electron gas, and then fit the data to a model to find out the type of exhibited.

Much recent work has examined the internal structure of electron states of these 10-nm-scale quantum dots, which are tiny, very efficient energy absorbers that can release energy at custom frequencies depending on their size. Self-assembled quantum dots hold great promise for inexpensive fabrication of all kinds of novel applications such as lasers, detectors, and , as well as in nanotechnology research. What is missing, says the team, is an understanding of the scattering effects of the electrons. Optimizing scattering may be useful as a way of efficiently transporting electrons and thereby maximizing the performance of quantum dot-based devices.

To study these effects, the researchers placed an AlGaAs/GaAs two-dimensional electron gas (2DEG) near embedded GaSb/GaAs type-II quantum dots at a temperature of 4.2 K.

"The type-II GaSb quantum dots only confine the holes and not the ," says coauthor Chao Jiang, "so they are free to interact with the 2DEG."

Measurements at various voltages in the coupled system showed that the scattering mechanism is short-range, an idea verified by a simple model with a constant scattering potential.

"For the first time, we have clarified that the mechanism of electron scattering in this type of quantum dot system is short-range," says Chao. "The result is particularly significant for the future designing of very efficient quantum-dot-based devices."

Explore further: Team finds electricity can be generated by dragging saltwater over graphene

More information: The article, "Short Range Scattering Mechanism of Type-II GaSb/GaAs Quantum Dots on the Transport Properties of Two-dimensional Electron Gas" by Chao Jiang, Guodong Li, Hong Yin (National Center for Nanoscience and Technology, China), Qinsheng Zhu (Chinese Academy of Science) and Hiroyuki Sakaki (Toyota Technological Institute) appears in the Journal of Applied Physics. link.aip.org/link/japiau/v108/i4/p043702/s1

Provided by American Institute of Physics

4.7 /5 (3 votes)

Related Stories

Encouraging quantum dots to emit photons

Aug 05, 2010

(PhysOrg.com) -- One of the fields of great interest to scientists and researchers is that of using the quantum world to enhance various aspects of our lives. Advances in quantum cryptography make headlines, and scientists ...

Quantum dots as midinfrared emitters

Feb 23, 2009

(PhysOrg.com) -- “People are interested in the mid-infrared,” Dan Wasserman tells PhysOrg.com. Infrared light has a wavelength longer than visible light, and many molecules have numerous very strong optical resonances in the ...

Recommended for you

'Exotic' material is like a switch when super thin

2 hours ago

(Phys.org) —Ever-shrinking electronic devices could get down to atomic dimensions with the help of transition metal oxides, a class of materials that seems to have it all: superconductivity, magnetoresistance ...

User comments : 0

More news stories

Innovative strategy to facilitate organ repair

A significant breakthrough could revolutionize surgical practice and regenerative medicine. A team led by Ludwik Leibler from the Laboratoire Matière Molle et Chimie (CNRS/ESPCI Paris Tech) and Didier Letourneur ...

'Exotic' material is like a switch when super thin

(Phys.org) —Ever-shrinking electronic devices could get down to atomic dimensions with the help of transition metal oxides, a class of materials that seems to have it all: superconductivity, magnetoresistance ...

LADEE mission ends with planned lunar impact

(Phys.org) —Ground controllers at NASA's Ames Research Center in Moffett Field, Calif., have confirmed that NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft impacted the surface ...