From Berkeley Lab: “Berkeley Lab Researchers Use Metamaterials to Observe Giant Photonic Spin Hall Effect”

Berkeley Lab

March 21, 2013
Lynn Yarris

“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.

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.

‘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.

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.

See the full article here.

A U.S. Department of Energy National Laboratory Operated by the University of California

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From Brookhaven Lab: “Sound, Light Sources and the Thrill of Glimpsing the Future”

Brookhaven Lab

February 28, 2013
Marc Allaire, Allen M. Orville and Alexei S. Soares

“Scientific research is a process fraught with fits and starts, dead-ends, dashed dreams, unexpected turns, and the occasional exhilarating insight. As scientists, many of us continue along our career path in part because of those rare moments of joy felt when contributing to the frontiers of science. We experienced one of those rare moments this past January at the National Synchrotron Light Source (NSLS) X25 beamline, when we successfully tested a new method to collect data from protein crystals—by using sound waves to eject the crystals through the air into an X-ray beam.

Members of the Photon Sciences Directorate team who collaborated in developing the acoustic droplet ejection system at the X25 beamline at Brookhaven Lab’s National Synchrotron Light Source: (far left) Marc Allaire, (front row, from right) Rick Jackimowicz, Anthony Kuczewski, Christian Roessler, (back row, from right) Annie Héroux, Allen M. Orville (also of the Biosciences Department), and Alexei S. Soares

For decades now, preparing microscopic protein crystals to collect data was done typically by hand with a microscope, and lassoing a crystal out of its liquid environment required great skill. After that was done, the sample would be transported from the lab to a beamline end station and then mechanically transferred into the X-ray beam, where we collected data to determine the atomic structure of complex macromolecules.

In contrast, this new method—called acoustic droplet ejection (ADE) —employs pulsed sound waves to eject crystals encased in a droplet from their source into the X-ray beam. This can be done with great precision, at high speeds, and without touching the crystals at all. We theorized that this was in fact possible back in 2008, but we were overcome with joy when, last month, we observed the first X-ray diffraction pattern from crystals with our new, automated ADE method.”

See the full article here.

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

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From Fermilab- “Frontier Science Result: CDF Advancing theory through precision measurements”

Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

Thursday, Jan. 24, 2013
edited by Andy Beretvas

“The detection of photons, produced in proton-antiproton collisions, plays an important role in particle physics by providing clean information about particle interactions. This is because photons produce an easily identifiable signal in the detector. In particular, events with two photons are of special interest because particles such as the boson discovered last year at the LHC, or the graviton, the hypothetical particle responsible for the gravitational force in quantum theories of gravity, decay into two photons.

This figure shows the photon pair-production probability (or cross section) as a function of the angle between the two photons in the plane normal to the proton beam. The bars show the statistical uncertainty and the shaded areas the systematic uncertainty of the measurement. The data points are the CDF measurements and the curves are predictions of various theories.

A team of Fermilab physicists identified all events with photon pairs detected in the CDF detector and measured some of their properties in two stages….”

Read the full article here.

Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics.

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From Brookhaven Lab: “Breakthrough Iron-based Superconductors Set New Performance Records”

Brookhaven Lab

New fabrication method could advance technologies ranging from medical imaging devices to grid-scale energy storage

January 9, 2013
Justin Eure
Peter Genze

“The road to a sustainably powered future may be paved with superconductors. When chilled to frigid temperatures hundreds of degrees Celsius below zero, these remarkable materials are singularly capable of perfectly conducting electric current. To meet growing global energy demands, the entire energy infrastructure would benefit tremendously from incorporating new electricity generation, storage, and delivery technologies that use superconducting wires. But strict limits on temperature, high manufacturing costs, and the dampening effects of high-magnetic fields currently impede widespread adoption.

Brookhaven physicists Weidong Si (left) and Qiang Li look into the vacuum chamber where the new high-field iron-based superconductors are made through a process called pulsed-laser deposition. No image credit.

Now, a collaboration led by scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have created a high performance iron-based superconducting wire that opens new pathways for some of the most essential and energy-intensive technologies in the world. These custom-grown materials carry tremendous current under exceptionally high magnetic fields—an order of magnitude higher than those found in wind turbines, magnetic resonance imaging (MRI) machines, and even particle accelerators. The results— published online January 8 in the journal Nature Communications—demonstrate a unique layered structure that outperforms competing low-temperature superconducting wires while avoiding the high manufacturing costs associated with high-temperature superconductor (HTS) alternatives.”

See the full article here.

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

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From Brookhaven: “Growing Cutting-edge X-ray Optics”

Brookhaven Lab

Scientists use a custom-designed machine and a reprogrammed Xbox controller to create atomically precise lenses

December 6, 2012
Justin Eure

“Unleashing some of the most promising energy technologies of tomorrow—from electric vehicle fuel cells to photovoltaics—hinges upon understanding tiny structures spanning just billionths of a meter. One way to explore this critical nanoscale world is by sending high-intensity x-ray beams through materials, similar to the way doctors capture images of internal bone structure using large x-ray devices. The challenge with fringe physics, however, is that focusing that penetrating power on just a single nanometer takes an entirely different caliber of lens.…”

See how it is done-

Is that cool, or what?

“Using a massive, custom-built deposition device, Brookhaven Lab scientist Ray Conley and his team are able to grow special lenses one atomic layer at a time. As intense x-rays pass through these multilayer Laue lenses (MLL), the light diffracts and bends toward a single point. Creating these atomically precise optics is no small feat, and Conley continues to tweak the process of growing light-bending films and carving them into precise lenses.”

See the full article here.

The completed MLLs will be deployed on beamlines at Brookhaven Lab’s forthcoming National Synchrotron Light Source II, one of the world’s most advanced light sources, to reveal unparalleled details of nanomaterial structures.

Brookhaven’s current light source — the National Synchrotron Light Source (NSLS) — is one of the world’s most widely used scientific facilities. Each year, 2,200 researchers from 400 universities, government laboratories, and companies use its bright beams of x-rays, ultraviolet light, and infrared light for research in such fields as biology, medicine, chemistry, environmental sciences, physics, and materials science. The scientific productivity of the NSLS user community is very high and has widespread impact, with more than 900 publications per year, many in premier scientific journals.

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

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From Brookhaven Lab: “Biologists Describe Details of New Mechanism for Molecular Interactions”

Brookhaven Lab

“Molecular sled” carries viral enzyme along DNA to find and interact with targets; findings suggest mechanism may be universal

October 10, 2012
Nick Statt

“Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, with collaborators from Harvard University, the University of Madrid, Princeton University, and the University of Zurich, have discovered a new mechanism that may alter principle understandings of molecular interactions within a cell’s nucleus. The discovery illustrates how two proteins of the human adenovirus use DNA as an efficient form of transportation inside a newly synthesized virus particle. The proteins use what the scientists are calling a molecular sled, which slides along the DNA double helix—much like a train running along its tracks—to find and interact with other proteins. In a series of four papers published back to back online October 7, 2012, in the Journal of Biological Chemistry under the title Regulation of a viral proteinase by a peptide and DNA in one-dimensional space, the group, led by Brookhaven biophysicist Walter F. Mangel, has raised the possibility that all proteins in the nucleus of cells interact by sliding on DNA in this fashion.”

Brookhaven biophysicist Walter F. Mangel

This is a far reaching “in depth” article about a very important and complex process. See the full article here.

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

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From MIT News: “Patterning defect-free nanocrystal films with nanometer resolution”

New process developed at MIT could enable better LED displays, solar cells and biosensors — and foster basic physics research.

August 20, 2012
David L. Chandler, MIT News Office

“Films made of semiconductor nanocrystals — tiny crystals measuring just a few billionths of a meter across — are seen as a promising new material for a wide range of applications. Nanocrystals could be used in electronic or photonic circuits, detectors for biomolecules, or the glowing pixels on high-resolution display screens. They also hold promise for more efficient solar cells.

Images of nanopatterned films of nano crystalline material produced by the MIT research team. Each row shows a different pattern produced on films of either cadmium selenide (top and bottom) or a combination of zinc cadmium selenide and zinc cadmium sulfur (middle row). The three images in each row are made using different kinds of microscopes: left to right, scanning electron microscope, optical (showing real-color fluorescence), and atomic force microscope. Images courtesy of Mentzel et al, from Nano Letters

Now, researchers at MIT say they have found ways of making defect-free patterns of nanocrystal films where the shape and position of the films are controlled with nanoscale resolution, potentially opening up a significant area for research and possible new applications.”

See the full article here.

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From MIT News: “Riding herd on photons”

A new metamaterial prevents electromagnetic waves from reflecting backward, pointing the way toward computer chips that move data with light.

August 3, 2012
Larry Hardesty

“Computer chips that use light to move data would be much more energy efficient and possibly even faster than today’s chips, which use electricity. One of the difficulties in realizing them, however, is that light moving through a “waveguide” — unlike electrons moving through a wire — can reflect backward, interfering with subsequent transmissions and even disrupting the operation of the laser that emitted it.

To prevent microwaves passing through it from reflecting backward, a new ‘metamaterial’ uses antennas of alternating orientations (top) that are connected by amplifier circuits (bottom).
Photo: Zheng Wang

In this week’s Proceedings of the National Academy of Sciences, researchers at MIT, Zhejiang University in China, and the University of Texas at Austin describe a new ‘metamaterial’ that keeps photons moving in only one direction, rechanneling the stragglers rather than simply absorbing them. Although the prototype is large, it doesn’t require the application of a magnetic field, so it could, in principle, yield optical components much smaller than today’s isolators. Moreover, building a chip-scale version of the metamaterial would require no materials more exotic than the metals already used in microprocessors, reducing manufacturing costs.

With isolators, ‘…you may not have reflection, but you lose light as light propagates in your structure…,’ says Zheng Wang, who led the research as a postdoc and research scientist at MIT and is now an assistant professor of computer and electrical engineering at the University of Texas. ‘Which is a big deal, because one of the reasons we don’t have large-scale integrated optical devices is that loss limits how many devices we can integrate in the system.’”

See the full article here.

From SLAC News Center: “Extreme Plasma Theories Put to the Test”

August 6, 2012
Andy Freeberg

“The first controlled studies of extremely hot, dense matter have overthrown the widely accepted 50-year-old model used to explain how ions influence each other’s behavior in a dense plasma. The results should benefit a wide range of fields, from research aimed at tapping nuclear fusion as an energy source to understanding the inner workings of stars.

The peaks on this chart represent key energy signatures produced in a dense ultrahot plasma, which for the first time allow detailed measurements of the effects of this plasma environment.

The study also demonstrates the unique capabilities of the Linac Coherent Light Source (LCLS) X-ray laser at the U.S. Department of Energy (DOE)’s SLAC National Accelerator Laboratory. While researchers have created extremely hot and dense plasmas before, LCLS allows them to measure the detailed properties of these states and test a fundamental class of plasma physics for the first time ever.

See the full article here.

‘We don’t think this could have been done elsewhere, said Justin Wark, leader of a group at Oxford University that participated in the study. ‘Having an X-ray laser is key.’”

SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.

From ISGTW: “The grand vision of the Cherenkov Telescope Array”

June 27, 2012
Adrian Giordani

“The Cherenkov Telescope Array (CTA) will consist of two arrays of telescopes in two different hemispheres, allowing full coverage of the sky. The south CTA will cover about one square kilometer (0.39 square miles) of land with around 60 telescopes that will monitor all the energy ranges in the center of the Milky Way’s galactic plane. The north CTA will cover three square kilometers (1.16 square miles) and be composed of 30 telescopes. These telescopes will be targeted at extragalactic astronomy.

An artist’s impression of the final constructed Cherenkov Telescope Array. Image courtesy G. Perez, SMM, IAC.

‘CTA opens a new window of essentially unexplored photon energies,’ said Giovanni Bignami, president of the Italian National Institute for Astrophysics (INAF). ‘Its potential impact is enormous: part of it, we imagine, will consist in discovering thousands of new [very-high-energy photon] sources, and part of it will be surprises. It’s the surprises we like best, and it’s the surprises that will most appeal to the public at large.’

The project represents a major global effort with research groups from Africa, Argentina, Brazil, India, Japan, Mexico, and the US. There are currently more than 27 countries, and over 1,000 scientists involved.

What is the goal of the CTA?

The project will be composed of a collection of Cherenkov telescopes that will scan the universe at very-high-energy gamma-rays from 100 giga-electronvolts to about 100 tera-electronvolts; energies which are one hundred billion to one hundred trillion times higher than of visible light.The CTA will also investigate cosmic processes that create particles travelling close to the speed of light.

The CTA combines the fields of astronomy, astrophysics, and fundamental physics research. Studies will include the origin of cosmic rays and their impact on other bodies within the universe. Researchers will investigate galactic particle accelerators, black holes, extragalactic gamma rays, dark matter, and the effects of quantum gravity.”

See the full article here.