Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Advancing information processing with exceptional points and surfaces

20.12.2019

Scientists at the U.S. Department of Energy's (DOE) Argonne National Laboratory are exceptional in many respects. Working in collaboration with the Imperial College London, for example, they have conducted research on a phenomenon in information processing systems called "exceptional points." This phenomenon has found applications in microwave, optical and mechanical technologies.

"Our team experimentally detected an exceptional surface, a continuous three-dimensional curving surface of exceptional points," said Xufeng Zhang, who led this international research project and works as an assistant scientist at the Center for Nanoscale Materials (CNM) at Argonne, a DOE Office of Science User Facility.


Left graph plots exceptional point conditions in three-dimensional space, calculated from experimental measurements in CNM, forming an exceptional surface with an exceptional saddle point, indicated by the point at the intersection of the dark lines on the surface. Right graph plots energy dissipations of the two modes (photon and magnon), where different dependences on the tuning parameters occur near the intersection of blue and red surfaces.

Credit: Argonne National Laboratory

Past research by others had detected exception points, and subsequent researchers had plotted lines of measured exceptional points, but this is the first time researchers have plotted surfaces.

"Our original contribution is to have mapped three-dimensional surfaces of exceptional points based on experimental measurements, and the result is strikingly beautiful graphs." -- Xufeng Zhang, assistant scientist at the Center for Nanoscale Materials

"Think of two systems, each of which has its own loss of energy to the environment," explained Zhang. "Also imagine that these systems are coupled so that they can exchange energy between them."

When these systems are far apart, little interaction occurs between them, and energy-related calculations yield two independent solutions tied to their interactions with the environment alone. As they approach each other and interact together, the systems enter a transition phase where there is only one solution.

That is considered an exceptional point. As the systems move even closer, the exceptional point vanishes, and the calculations yield pairs of "hybrid solutions," a mixture of the solutions for each system.

A possible application of exceptional points is sensors with greatly enhanced sensitivity to disruptions such as slight fluctuations in a magnetic field. Another application is mode conversion, which allows, for example, the signals from the two parties in a telephone call to be kept in separate modes, thereby essentially eliminating any undesired interference.

"Our original contribution is to have mapped three-dimensional surfaces of exceptional points based on experimental measurements, and the result is strikingly beautiful graphs," Zhang said. These exceptional surfaces themselves have what Zhang calls "exceptional saddle points," the most exceptional point among all the other exceptional points on the surfaces. These saddle points have heightened desired behavior over the other exceptional points.

The team's experimental apparatus combines two systems: a specialized printed circuit board that confines microwaves and a microscale magnetic sphere of yttrium iron garnet, which produces resonances called "magnons."

"Magnons are quantized quasiparticles associated with spin waves, a collective excitation of the magnetic ordering in a crystal lattice," Zhang explained. "What is important here is that changing the magnetization at one point in the lattice affects the neighboring sites like a wave rippling through the surface of a placid pond."

The team used a magneto-electro-optical spectrometer at the CNM to measure the response to different tunings of the photon-magnon coupling strength and position in their apparatus, then plotted the results in three-dimensional graphs of an exceptional surface.

While highly abstract and mathematical, this pivotal discovery could have real world impact in information processing. As one of several possible examples, information transfer demands that noise not corrupt the zeros and ones being transmitted, and exceptional surface mapping could help provide much greater protection for this process.

"Our work also opens up exciting new possibilities for quantum information processing with highly desired functionalities," Zhang noted.

###

The researchers' work described above appears in Physical Review Letters and is entitled "Experimental observation of an exceptional surface in synthetic dimensions with magnon polaritons." In addition to the corresponding author Zhang, co-authors include Kun Ding at Imperial College London, and Argonne CNM researchers Xianjing Zhou, Jing Xu and Dafei Jin.

This work was supported by the DOE Office of Basic Energy Sciences and was performed in part at Argonne's Center for Nanoscale Materials.

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/advancing-information-processing-with-exceptional-points-and-surfaces
http://dx.doi.org/10.1103/PhysRevLett.123.237202

More articles from Materials Sciences:

nachricht First detailed electronic study of new nickelate superconductor finds 3D metallic state
22.01.2020 | DOE/SLAC National Accelerator Laboratory

nachricht A new look at 'strange metals'
21.01.2020 | Vienna University of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New roles found for Huntington's disease protein

Crucial role in synapse formation could be new avenue toward treatment

A Duke University research team has identified a new function of a gene called huntingtin, a mutation of which underlies the progressive neurodegenerative...

Im Focus: A new look at 'strange metals'

For years, a new synthesis method has been developed at TU Wien (Vienna) to unlock the secrets of "strange metals". Now a breakthrough has been achieved. The results have been published in "Science".

Superconductors allow electrical current to flow without any resistance - but only below a certain critical temperature. Many materials have to be cooled down...

Im Focus: Programmable nests for cells

KIT researchers develop novel composites of DNA, silica particles, and carbon nanotubes -- Properties can be tailored to various applications

Using DNA, smallest silica particles, and carbon nanotubes, researchers of Karlsruhe Institute of Technology (KIT) developed novel programmable materials....

Im Focus: Miniature double glazing: Material developed which is heat-insulating and heat-conducting at the same time

Styrofoam or copper - both materials have very different properties with regard to their ability to conduct heat. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz and the University of Bayreuth have now jointly developed and characterized a novel, extremely thin and transparent material that has different thermal conduction properties depending on the direction. While it can conduct heat extremely well in one direction, it shows good thermal insulation in the other direction.

Thermal insulation and thermal conduction play a crucial role in our everyday lives - from computer processors, where it is important to dissipate heat as...

Im Focus: Fraunhofer IAF establishes an application laboratory for quantum sensors

In order to advance the transfer of research developments from the field of quantum sensor technology into industrial applications, an application laboratory is being established at Fraunhofer IAF. This will enable interested companies and especially regional SMEs and start-ups to evaluate the innovation potential of quantum sensors for their specific requirements. Both the state of Baden-Württemberg and the Fraunhofer-Gesellschaft are supporting the four-year project with one million euros each.

The application laboratory is being set up as part of the Fraunhofer lighthouse project »QMag«, short for quantum magnetometry. In this project, researchers...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
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

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

 
Latest News

New self-assembled monolayer is resistant to air

22.01.2020 | Life Sciences

Ultrafast camera takes 1 trillion frames per second of transparent objects and phenomena

22.01.2020 | Power and Electrical Engineering

Mosquitoes are drawn to flowers as much as people -- and now scientists know why

22.01.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>