Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Advance brings 'hyperbolic metamaterials' closer to reality

"Hyperbolic metamaterials" could bring optical advances including powerful microscopes, quantum computers and high-performance solar cells. The graphic at left depicts a metamaterial's "hyperbolic dispersion" of light. At center is a high-resolution transmission electron microscope image showing the interface of titanium nitride and aluminum scandium nitride in a "superlattice" that is promising for potential applications. At right are two images created using a method called fast Fourier transform to see individual layers in the material. Purdue University image
"Hyperbolic metamaterials" could bring optical advances including powerful microscopes, quantum computers and high-performance solar cells. The graphic at left depicts a metamaterial's "hyperbolic dispersion" of light. At center is a high-resolution transmission electron microscope image showing the interface of titanium nitride and aluminum scandium nitride in a "superlattice" that is promising for potential applications. At right are two images created using a method called fast Fourier transform to see individual layers in the material.

Purdue University image

Abstract:
Epitaxial superlattices with titanium nitride as a plasmonic component for optical hyperbolic metamaterials

Gururaj V. Naik,1 Bivas Saha,2 Jing Liu,3 Sammy M. Saber,2 Eric Stach,2 Joseph MK Irudayaraj,3 Timothy D. Sands,1,2 Vladimir M. Shalaev1 and Alexandra Boltasseva*,1,4

1 School of Electrical and Computer Engineering, and Birck Nanotechnology Center, Purdue

University

2 School of Materials Engineering, and Birck Nanotechnology Center, Purdue University

3 Department of Agricultural and Biological Engineering, and Bindley Bioscience Center,

Purdue University

4 DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark CORRESPONDING AUTHOR: *Alexandra Boltasseva

Titanium nitride (TiN) is a plasmonic material having optical properties resembling gold. Unlike gold however, TiN is CMOS-compatible, mechanically strong, and thermally stable at higher temperatures. Additionally, TiN can be grown in smooth, ultra-thin crystalline films, which are useful in constructing many plasmonic and metamaterial devices including hyperbolic metamaterials (HMMs). Hyperbolic metamaterials have been shown to exhibit exotic optical properties, including extremely high broadband photonic densities of states (PDOS), which are useful in quantum plasmonics applications. However, the extent to which the exotic properties of HMMs can be realized has been seriously limited by fabrication constraints and material properties. Here, we address these issues by realizing an epitaxial superlattice as an HMM. The superlattice consists of ultra-smooth layers as thin as 5 nm and exhibits sharp interfaces, which are essential for high-quality HMM devices. Our study reveals that such a TiN-based superlattice HMM provides a higher PDOS enhancement than gold- or silver-based HMMs. Given the advantages of TiN as a CMOS compatible plasmonic material, this demonstration brings a paradigm shift to the field of metamaterials similar to the way heterostructures did to the field of solid-state light sources.

Advance brings 'hyperbolic metamaterials' closer to reality

West Lafayette, IN | Posted on May 15th, 2014

Researchers have taken a step toward practical applications for "hyperbolic metamaterials," ultra-thin crystalline films that could bring optical advances including powerful microscopes, quantum computers and high-performance solar cells.

New developments are reminiscent of advances that ushered in silicon chip technology, said Alexandra Boltasseva, a Purdue University associate professor of electrical and computer engineering.

Optical metamaterials harness clouds of electrons called surface plasmons to manipulate and control light. However, some of the plasmonic components under development rely on the use of metals such as gold and silver, which are incompatible with the complementary metal-oxide-semiconductor (CMOS) manufacturing process used to construct integrated circuits and do not transmit light efficiently.

Now researchers have shown how to create "superlattice" crystals from layers of the metal titanium nitride and aluminum scandium nitride, a dielectric, or insulator. Superlattices are crystals that can be grown continuously by adding new layers, a requirement for practical application.

"This work is a very important step in terms of fundamental contributions in materials science and optics as well as paving the way to some interesting applications," Boltasseva said. "We believe this demonstration brings a paradigm shift to the field of metamaterials similar to developments that led to dramatic advances in silicon technology."

Research findings are detailed in a paper appearing this week in the online Early Edition of Proceedings of the National Academy of Sciences.

Researchers created the superlattices using a method called epitaxy, "growing" the layers inside a vacuum chamber with a technique known as magnetron sputtering. It is difficult to use the technique to create structures that have sharply defined, ultra-thin and ultra-smooth layers of two different materials.

"This is one of the first reports of a metal-dielectric epitaxial superlattice," said Purdue doctoral student Bivas Saha, co-lead author of the PNAS paper with Gururaj V. Naik, a former Purdue doctoral student and now a postdoctoral scholar at Stanford University.

The list of possible applications for metamaterials includes a "planar hyperlens" that could make optical microscopes 10 times more powerful and able to see objects as small as DNA, advanced sensors, more efficient solar collectors, and quantum computing.

"Plasmonic and metamaterial devices require good material building blocks, both plasmonic and dielectric, in order to be useful in any real-world application," Boltasseva said. "Here, we develop both plasmonic and dielectric materials that can be grown epitaxially into ultra-thin and ultra-smooth layers with sharp interfaces."

Metamaterials have engineered surfaces that contain features, patterns or elements, such as tiny antennas or alternating layers of nitrides that enable unprecedented control of light. Under development for about 15 years, the metamaterials owe their unusual potential to precision design on the scale of nanometers.

The PNAS paper was authored by Naik; Saha; doctoral students Jing Liu and Sammy M. Saber; Eric Stach, a researcher at Brookhaven National Laboratory; Joseph Irudayaraj, a professor in Purdue's Department of Agricultural and Biological Engineering; Timothy D. Sands, executive vice president for academic affairs and provost and Basil S. Turner Professor of Engineering in the Schools of Materials Engineering and Electrical and Computer Engineering; Vladimir M. Shalaev, scientific director of nanophotonics at Purdue's Birck Nanotechnology Center and a distinguished professor of electrical and computer engineering; and Boltasseva.

"This work results from a unique collaboration between nanophotonics and materials science," Boltasseva said.

The hyperbolic metamaterial behaves as a metal when light is passing through it in one direction and like a dielectric in the perpendicular direction. This "extreme anisotropy" leads to "hyperbolic dispersion" of light and the ability to extract many more photons from devices than otherwise possible, resulting in high performance.

The layers of titanium nitride and aluminum scandium nitride used in this study are each about 5 to 20 nanometers thick. However, researchers have demonstrated that such superlattices can also be developed where the layers could be as thin as 2 nanometers, a tiny dimension only about eight atoms thick.

"People have tried for more than 50 years to combine metals and semiconductors with atomic-scale precision to build superlattices," Saha said. "However, this is one of the first demonstrations of achieving that step. The fascinating optical properties we see here are a manifestation of extraordinary structural control that we have achieved."

The feat is possible by choosing a metal and dielectric with compatible crystal structures, enabling the layers to grow together as a superlattice. The researchers alloyed aluminum nitride with scandium nitride, meaning the aluminum nitride is impregnated with scandium atoms to alter the material's crystal lattice to match titanium nitride's.

"The possibility of growing both metal and dielectric material components as a whole epitaxial system is indispensable for realizing high-performance metamaterials," Saha said. "One of the stumbling blocks is the fact that common dielectrics such as silica, alumina and other oxides cannot be used in combination with metallic components such as metal nitrides because the deposition processes are not compatible with each other."

Both of the materials should possess the same or compatible crystal structures.

"In general, a lattice mismatch of less than 5 percent is necessary for growing epitaxial quality films," he said.

A U.S. patent application has been filed through the Purdue Office of Technology Commercialization.

The material has been shown to work in a broad spectrum from near-infrared to visible light, potentially promising a wide array of applications.

"That's a novel part of this work - that we can create a superlattice metamaterial showing hyperbolic dispersion in the visible spectrum range," Boltasseva said.

The near-infrared is essential for telecommunications and optical communications, and visible light is important for sensors, microscopes and efficient solid-state light sources.

"Most interesting is the realm of quantum information technology," she said.

Computers based on quantum physics would have quantum bits, or "qubits," that exist in both the on and off states simultaneously, dramatically increasing the computer's power and memory. Quantum computers would take advantage of a phenomenon described by quantum theory called "entanglement." Instead of only the states of one and zero used in conventional computer processing, there are many possible "entangled quantum states" in between one and zero, increasing the capacity to process information.

The research has been funded in part by the U.S. Army Research Office and the National Science Foundation.

####

For more information, please click here

Contacts:
Writer:
Emil Venere

765-494-4709

Sources:
Alexandra Boltasseva
765-494-0301


Bivas Saha

Copyright © Purdue University

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 News Press

News and information

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

Nano-watch has steady hands November 21st, 2017

Nano Global, Arm Collaborate on Artificial Intelligence Chip to Drive Health Revolution by Capturing and Analyzing Molecular Data in Real Time November 21st, 2017

Nanoparticles could allow for faster, better medicine: Exposure of nanoparticles in the body allows for more effective delivery November 20th, 2017

Imaging

The stacked color sensor: True colors meet minimization November 16th, 2017

Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs November 8th, 2017

LuleŚ University of Technology is using the Deben CT5000TEC stage to perform x-ray microtomography experiments with the ZEISS Xradia 510 Versa to understand deformation and strain inside inhomogeneous materials November 7th, 2017

Quorum reports on how cryo prep techniques for SEM are being applied in the Laboratory of Food Technology & Engineering at the University of Ghent, Belgium November 7th, 2017

Thin films

MIPT scientists revisit optical constants of ultrathin gold films October 20th, 2017

Rice University chemists make laser-induced graphene from wood July 31st, 2017

Graduate Students from Across the Country Attend Hands-on NanoCamp: Prominent scientists Warren Oliver, Ph.D., and George Pharr, Ph.D., presented a weeklong NanoCamp for hand-picked graduate students across the United States July 26th, 2017

Studying Argon Gas Trapped in Two-Dimensional Array of Tiny "Cages": Understanding how individual atoms enter and exit the nanoporous frameworks could help scientists design new materials for gas separation and nuclear waste remediation July 17th, 2017

Govt.-Legislation/Regulation/Funding/Policy

EC Project Aims at Creating and Commercializing Cyber-Physical-System Solutions November 14th, 2017

Nanobiotix presented new clinical and pre-clinical data confirming NBTXR3ís significant potential role in Immuno-Oncology at SITC Annual Meeting November 14th, 2017

Leti Joins DARPA-Funded Project to Develop Implantable Device for Restoring Vision November 9th, 2017

Nanoshells could deliver more chemo with fewer side effects: In vitro study verifies method for remotely triggering release of cancer drugs November 8th, 2017

Quantum Computing

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

Quantum communications bend to our needs: By changing the wavelengths of entangled photons to those used in telecommunications, researchers see quantum technology take a major leap forward September 28th, 2017

Discoveries

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

Nano-watch has steady hands November 21st, 2017

Nanoparticles could allow for faster, better medicine: Exposure of nanoparticles in the body allows for more effective delivery November 20th, 2017

ICN2 researchers compute unprecedented values for spin lifetime anisotropy in graphene November 17th, 2017

Materials/Metamaterials

ICN2 researchers compute unprecedented values for spin lifetime anisotropy in graphene November 17th, 2017

Math gets real in strong, lightweight structures: Rice University researchers use 3-D printers to turn century-old theory into complex schwarzites November 16th, 2017

A new way to mix oil and water: Condensation-based method developed at MIT could create stable nanoscale emulsions November 8th, 2017

TUBALL nanotube-based concentrates recognised as the most innovative raw material for composites by JEC Group November 7th, 2017

Announcements

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

Nano-watch has steady hands November 21st, 2017

Nano Global, Arm Collaborate on Artificial Intelligence Chip to Drive Health Revolution by Capturing and Analyzing Molecular Data in Real Time November 21st, 2017

Nanoparticles could allow for faster, better medicine: Exposure of nanoparticles in the body allows for more effective delivery November 20th, 2017

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

Nano-watch has steady hands November 21st, 2017

Nanoparticles could allow for faster, better medicine: Exposure of nanoparticles in the body allows for more effective delivery November 20th, 2017

ICN2 researchers compute unprecedented values for spin lifetime anisotropy in graphene November 17th, 2017

Tools

Nanometrics to Participate in the 6th Annual NYC Investor Summit 2017 November 16th, 2017

Nanometrics Announces $50 Million Share Repurchase Program November 15th, 2017

Nanometrics Board of Directors Names Pierre-Yves Lesaicherre President and CEO November 14th, 2017

Oxford Instruments announces winner of the 2017 Sir Martin Wood Prize for Japan November 14th, 2017

Patents/IP/Tech Transfer/Licensing

Picosunís ALD nanolaminates improve lifetime and reliability of electronic circuit boards October 24th, 2017

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Nanoparticles limit damage in spinal cord injury: Injection after an injury reduces inflammation and scarring September 6th, 2017

More durable, less expensive fuel cells: University of Delaware researchers have developed a new technology that could speed up the commercialization of fuel cell vehicles September 5th, 2017

Military

Math gets real in strong, lightweight structures: Rice University researchers use 3-D printers to turn century-old theory into complex schwarzites November 16th, 2017

Promising sensors for submarines, mines and spacecraft: MSU scientists are developing nanostructured gas sensors that would work at room temperature November 10th, 2017

Leti Joins DARPA-Funded Project to Develop Implantable Device for Restoring Vision November 9th, 2017

Nanoshells could deliver more chemo with fewer side effects: In vitro study verifies method for remotely triggering release of cancer drugs November 8th, 2017

Energy

Inorganic-organic halide perovskites for new photovoltaic technology November 6th, 2017

Dendritic fibrous nanosilica: all-in-one nanomaterial for energy, environment and health November 4th, 2017

New nanomaterial can extract hydrogen fuel from seawater: Hybrid material converts more sunlight and can weather seawater's harsh conditions October 4th, 2017

Researchers set time limit for ultrafast perovskite solar cells September 22nd, 2017

Photonics/Optics/Lasers

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

Math gets real in strong, lightweight structures: Rice University researchers use 3-D printers to turn century-old theory into complex schwarzites November 16th, 2017

Practical superconducting nanowire single photon detector with record detection efficiency over 90 percent November 9th, 2017

Metal-silicone microstructures could enable new flexible optical and electrical devices: Laser-based method creates force-sensitive, flexible microstructures that conduct electricity November 1st, 2017

Solar/Photovoltaic

Inorganic-organic halide perovskites for new photovoltaic technology November 6th, 2017

New nanomaterial can extract hydrogen fuel from seawater: Hybrid material converts more sunlight and can weather seawater's harsh conditions October 4th, 2017

Researchers set time limit for ultrafast perovskite solar cells September 22nd, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Quantum nanoscience

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

'Find the Lady' in the quantum world: International team of researchers presents method for quantum-mechanical swapping of positions October 18th, 2017

What can be discovered at the junction of physics and chemistry October 6th, 2017

Energy against the current on a quantum scale, without contradicting the laws of physics: A piece of research in which the UPV/EHU-University of the Basque Country has participated confirms that merely observing a flow of energy or particles can change its direction October 6th, 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