Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Shaping nanoparticles for improved quantum information technology

15.10.2019

Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.

Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National Laboratory, have contributed to a recently published Nature Communications paper that reports the cause behind a key quantum property of donut-like nanoparticles called "semiconductor quantum rings." 


This is an artistic rendering of semiconductor quantum rings being illuminated by a laser and emitting single photons.

Credit: Argonne National Laboratory

This property may find application in quantum information storage, communication, and computing in future technologies.

"If you illuminate a two-dimensional photon emitter with a laser, you expect them to emit light along two axes, but what you expect is not necessarily what you get. To our surprise, these two-dimensional rings can emit light along one axis." -- Xuedan Ma, assistant scientist, Center for Nanoscale Materials

In this project, the CNM researchers collaborated with colleagues from the University of Chicago, Ludwig Maximilian University of Munich, University of Ottawa and National Research Council in Canada.

The team assembled circular rings made out of cadmium selenide, a semiconductor that lends itself to growing donut-shaped nanoparticles. These quantum rings are two-dimensional structures -- crystalline materials composed of a few layers of atoms. The advantage of semiconductors is that when researchers excite them with a laser, they emit photons.

"If you illuminate a two-dimensional photon emitter with a laser, you expect them to emit light along two axes," said Xuedan Ma, assistant scientist at CNM. "But what you expect is not necessarily what you get. To our surprise, these two-dimensional rings can emit light along one axis."

The team observed this effect when breaking the perfect rotational symmetry of the donut shape, causing them to be slightly elongated. "By this symmetry breaking," says Ma, "we can change the direction of light emission. We can thus control how photons come out of the donut and achieve coherent directional control."

Because the photons in the light emits from these rings along a single direction, rather than spreading out in all directions, researchers can tune this emission to effectively collect single photons. With this control, researchers can integrate topology information into the photons, which can then be used as messengers for carrying quantum information. It may even be possible to exploit these encoded photons for quantum networking and computation.

"If we can gain even greater control over the fabrication process, we could make nanoparticles with different shapes such as a clover with multiple holes or a rectangle with a hole in the center," noted Matthew Otten, a Maria Goeppert Mayer Fellow at Argonne's CNM. "Then, we might be able to encode more types of quantum information or more information into the nanoparticles."

"I should add that geometry is not the only factor in causing this quantum effect. The atomistic structure of the material also counts, as is often the case in nanoscale materials," said Ma.

A paper based on the study, "Uniaxial transition dipole moments in semiconductor quantum rings caused by broken rotational symmetry," appeared recently in Nature Communications. In addition to Ma and Otten, authors include Nicolai F. Hartmann, Igor Fedin, Dmitri Talapin, Moritz Cygorek, Pawel Hawrylak, Marek Korkusinski, Stephen Gray and Achim Hartschuh.

###

This work was supported by the DOE Office of Science.

About Argonne's Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE's Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

Media Contact

Diana Anderson
ddanderson@anl.gov
630-252-4593

 @argonne

http://www.anl.gov 

Diana Anderson | EurekAlert!
Further information:
https://www.anl.gov/article/shaping-nanoparticles-for-improved-quantum-information-technology
http://dx.doi.org/10.1038/s41467-019-11225-6

More articles from Information Technology:

nachricht Intelligent Deletion of Superfluous Digital Files
21.02.2020 | Otto-Friedrich-Universität Bamberg

nachricht High-Performance Computing Center of the University of Stuttgart Receives new Supercomuter "Hawk"
19.02.2020 | Universität Stuttgart

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

Im Focus: Skyrmions like it hot: Spin structures are controllable even at high temperatures

Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices

The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...

Im Focus: Making the internet more energy efficient through systemic optimization

Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.

Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.

Im Focus: New synthesis methods enhance 3D chemical space for drug discovery

After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.

"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

NUI Galway highlights reproductive flexibility in hydractinia, a Galway bay jellyfish

24.02.2020 | Life Sciences

KIST researchers develop high-capacity EV battery materials that double driving range

24.02.2020 | Materials Sciences

How earthquakes deform gravity

24.02.2020 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>