Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Berkeley Lab Researchers Use Metamaterials to Observe Giant Photonic Spin Hall Effect

Light propagating through a metamaterial follows a curved trajectory that drags light with different circular polarization in opposite transverse directions to produce a giant photonic Spin Hall effect.
Light propagating through a metamaterial follows a curved trajectory that drags light with different circular polarization in opposite transverse directions to produce a giant photonic Spin Hall effect.

Abstract:
Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have once again demonstrated the incredible capabilities of metamaterials - artificial nanoconstructs whose optical properties arise from their physical structure rather than their chemical composition. Engineering a unique two-dimensional sheet of gold nanoantennas, the researchers were able to obtain the strongest signal yet of the photonic spin Hall effect, an optical phenomenon of quantum mechanics that could play a prominent role in the future of computing.

Berkeley Lab Researchers Use Metamaterials to Observe Giant Photonic Spin Hall Effect

Berkeley, CA | Posted on March 21st, 2013

"With metamaterial, we were able to greatly enhance a naturally weak effect to the point where it was directly observable with simple detection techniques," said Xiang Zhang, a faculty scientist with Berkeley Lab's Materials Sciences Division who led this research. "We also demonstrated that metamaterials not only allow us to control the propagation of light but also allows control of circular polarization. This could have profound consequences for information encoding and processing."

Zhang is the corresponding author of a paper describing this work in the journal Science. The paper is titled "Photonic Spin Hall Effect at Metasurfaces." Co-authors are Xiaobo Yin, Ziliang Ye, Jun Sun Rho and Yuan Wang.

The spin Hall effect, named in honor of physicist Edwin Hall, describes the curved path that spinning electrons follow as they move through a semiconductor. The curved movement arises from the interaction between the physical motion of the electron and its spin - a quantized angular momentum that gives rise to magnetic moment. Think of a baseball pitcher putting spin on a ball to make it curve to the left or right.

"Light moving through a metal also displays the spin Hall effect but the photonic spin Hall effect is very weak because the spin angular momentum of photons and spin-orbit interactions are very small," says Xiaobo Yin, a member of Zhang's research group and the lead author of the Science paper. "In the past, people have managed to observe the photonic spin Hall effect by generating the process over and over again to obtain an accumulative signal, or by using highly sophisticated quantum measurements. Our metamaterial makes the photonic spin Hall effect observable even with a simple camera."

Metamaterials have garnered a lot of attention in recent years because their unique structure affords electromagnetic properties unattainable in nature. For example, a metamaterial can have a negative index of refraction, the ability to bend light backwards, unlike all materials found in nature, which bend light forward. Zhang, who holds the Ernest S. Kuh Endowed Chair Professor of Mechanical Engineering at the University of California (UC) Berkeley, where he also directs the National Science Foundation's Nano-scale Science and Engineering Center, has been at the forefront of metamaterials research. For this study, he and his group fashioned metamaterial surfaces about 30 nanometers thick (a human hair by comparison is between 50,000 and 100,000 nanometers thick). These metasurfaces were constructed from V-shaped gold nanoantennas whose geometry could be configured by adjusting the length and orientation of the arms of the Vs.

"We chose eight different antenna configurations with optimized geometry parameters to generate a linear phase gradient along the x direction," says Yin. "This enabled us to control the propagation of the light and introduce strong photon spin-orbit interactions through rapid changes in direction. The photonic spin Hall effect depends on the curvature of the light's trajectory, so the sharper the change in propagation direction, the stronger the effect."

Since the entire metasurface sample measured only 0.3 millimeters, a 50-millimeter lens was used to project the transmission of the light through the metamaterial onto a charge-coupled device (CCD) camera for imaging. From the CCD images, the researchers determined that both the control of light propagation and the giant photonic spin Hall effect were the direct results of the designed meta-material. This finding opens up a wealth of possibilities for new technologies.

"The controllable spin-orbit interaction and momentum transfer between spin and orbital angular momentum allows us to manipulate the information encoded on the polarization of light, much like the 0 and 1 of today's electronic devices," Yin says. "But photonic devices could encode more information and provide greater information security than conventional electronic devices."

Yin says the ability to control left and right circular polarization of light in metamaterial surfaces should allow for the formation of optical elements, like highly coveted "flat lenses," or the management of light polarization without using wave plates.

"Metamaterials provide us with tremendous design freedom that will allow us to modulate the strength of the photonic spin Hall effect at different spatial locations," Yin says. "We knew the photonic spin Hall effect existed in nature but it was so hard to detect. Now, with the right metamaterials we can not only enhance this effect we can harness it for our own purposes."

This research was supported by the DOE Office of Science.

####

About Berkeley Lab
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’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, please visit the Office of Science website at science.energy.gov/.

For more information, please click here

Contacts:
Lynn Yarris
(510) 486-5375

Copyright © Berkeley Lab

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

For more information about the research of Xiang Zhang go here:

Related News Press

News and information

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

Laboratories

Alloying materials of different structures offers new tool for controlling properties June 19th, 2017

Development of low-dimensional nanomaterials could revolutionize future technologies June 15th, 2017

X-ray Study Reveals Way to Control Molecular Vibrations that Transmit Heat: Findings open new pathway for "tuning" materials to ease or insulate against the flow of heat, sound, and other forms of energy June 7th, 2017

Scientists Design Molecular System for Artificial Photosynthesis: System is designed to mimic key functions of the photosynthetic center in green plants to convert solar energy into chemical energy stored by hydrogen fuel June 2nd, 2017

Govt.-Legislation/Regulation/Funding/Policy

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Spintronics

Smart multi-layered magnetic material acts as an electric switch: New study reveals characteristic of islands of magnetic metals between vacuum gaps, displaying tunnelling electric current March 1st, 2017

First experimental proof of a 70 year old physics theory: First observation of magnetic phase transition in 2-D materials, as predicted by the Nobel winner Onsager in 1943 January 6th, 2017

Investigations of the skyrmion Hall effect reveal surprising results: One step further towards the application of skyrmions in spintronic devices December 28th, 2016

Electron highway inside crystal December 12th, 2016

Quantum Computing

Microsoft, Purdue collaborate to advance quantum computing May 30th, 2017

Looking for the quantum frontier: Beyond classical computing without fault-tolerance? April 27th, 2017

Harris & Harris Group Issues Its Financial Statements as of December 31, 2016, Posts Its Annual Shareholder Letter, And Will Host a Conference Call for Shareholders on Friday, March 17, 2017 March 15th, 2017

Sorting machine for atoms:Researchers at the University of Bonn clear a further hurdle on the path to creating quantum computers February 10th, 2017

Discoveries

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Announcements

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

Photonics/Optics/Lasers

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

New carbon nitride material coupled with ruthenium enhances visible-light CO2 reduction in water June 15th, 2017

Changing the color of laser light on the femtosecond time scale: How BiCoO3 achieves second harmonic generation June 14th, 2017

Learning with light: New system allows optical “deep learning”: Neural networks could be implemented more quickly using new photonic technology June 12th, 2017

Quantum nanoscience

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Oxford Instruments congratulates Lancaster University for inaugurating the IsoLab, built for studying quantum systems June 20th, 2017

In atomic propellers, quantum phenomena can mimic everyday physics June 1st, 2017

Unveiling the quantum necklace: Researchers simulate quantum necklace-like structures in superfluids May 26th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project