Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

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

Sopping up proteins with thermosponges: Researchers develop novel nanoparticle platform that proves effective in delivering protein-based drugs October 22nd, 2014

Brookhaven Lab Launches Computational Science Initiative:Leveraging computational science expertise and investments across the Laboratory to tackle "big data" challenges October 22nd, 2014

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

Imaging

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Special UO microscope captures defects in nanotubes: University of Oregon chemists provide a detailed view of traps that disrupt energy flow, possibly pointing toward improved charge-carrying devices October 21st, 2014

Thin films

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Govt.-Legislation/Regulation/Funding/Policy

Brookhaven Lab Launches Computational Science Initiative:Leveraging computational science expertise and investments across the Laboratory to tackle "big data" challenges October 22nd, 2014

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Quantum Computing

1980s aircraft helps quantum technology take flight October 20th, 2014

Australian teams set new records for silicon quantum computing October 12th, 2014

Ultrafast remote switching of light emission October 2nd, 2014

Quantum environmentalism: Putting a qubit's surroundings to good use October 2nd, 2014

Discoveries

Sopping up proteins with thermosponges: Researchers develop novel nanoparticle platform that proves effective in delivering protein-based drugs October 22nd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Mechanism behind nature's sparkles revealed October 22nd, 2014

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Materials/Metamaterials

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Materials for the next generation of electronics and photovoltaics: MacArthur Fellow develops new uses for carbon nanotubes October 21st, 2014

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Could I squeeze by you? Ames Laboratory scientists model molecular movement within narrow channels of mesoporous nanoparticles October 21st, 2014

Announcements

NanoTechnology for Defense (NT4D) October 22nd, 2014

Mechanism behind nature's sparkles revealed October 22nd, 2014

TARA Biosystems and Harris & Harris Group Form Company to Improve Safety and Efficacy of New Therapies October 22nd, 2014

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

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

Sopping up proteins with thermosponges: Researchers develop novel nanoparticle platform that proves effective in delivering protein-based drugs October 22nd, 2014

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

Tools

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Special UO microscope captures defects in nanotubes: University of Oregon chemists provide a detailed view of traps that disrupt energy flow, possibly pointing toward improved charge-carrying devices October 21st, 2014

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Detecting Cancer Earlier is Goal of Rutgers-Developed Medical Imaging Technology: Rare earth nanocrystals and infrared light can reveal small cancerous tumors and cardiovascular lesions October 21st, 2014

Patents/IP/Tech Transfer/Licensing

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Nanodevices for clinical diagnostic with potential for the international market: The development is based on optical principles and provides precision and allows saving vital time for the patient October 15th, 2014

Aculon Receives Patent for Application of Enhanced Bonding Layers on Titanium October 9th, 2014

harmaEngine will join Nanobiotix’ pivotal trial for NBTXR3 in Soft Tissue Sarcoma to accelerate its development in Asia-Pacific: PharmaEngine to make milestone payment to Nanobiotix in October 2014 to recognize the value created October 8th, 2014

Military

NanoTechnology for Defense (NT4D) October 22nd, 2014

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

1980s aircraft helps quantum technology take flight October 20th, 2014

Energy

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Could I squeeze by you? Ames Laboratory scientists model molecular movement within narrow channels of mesoporous nanoparticles October 21st, 2014

First Canada Excellence Research Chair gets $10 million from the federal government for oilsands research at the University of Calgary: Federal government announces prestigious research chair to study improving oil production efficiency October 19th, 2014

Magnetic mirrors enable new technologies by reflecting light in uncanny ways October 16th, 2014

Photonics/Optics/Lasers

Physicists build reversible laser tractor beam October 20th, 2014

Magnetic mirrors enable new technologies by reflecting light in uncanny ways October 16th, 2014

New VDMA Association "Electronics, Micro and Nano Technologies" founded: Inaugural Meeting in Frankfurt/Main, Germany October 15th, 2014

Nanodevices for clinical diagnostic with potential for the international market: The development is based on optical principles and provides precision and allows saving vital time for the patient October 15th, 2014

Solar/Photovoltaic

Magnetic mirrors enable new technologies by reflecting light in uncanny ways October 16th, 2014

Dyesol Signs Letter of Intent with Tata Steel October 13th, 2014

DNA nano-foundries cast custom-shaped metal nanoparticles: DNA's programmable assembly is leveraged to form precise 3D nanomaterials for disease detection, environmental testing, electronics and beyond October 10th, 2014

Over 100 European experts meet in Barcelona thanks to a COST Action coordinated from ICN2: The ISOS-7 Summit discusses the future of organic photovoltaic devices October 7th, 2014

Quantum nanoscience

NIST quantum probe enhances electric field measurements October 8th, 2014

Quantum environmentalism: Putting a qubit's surroundings to good use October 2nd, 2014

Rice launches Center for Quantum Materials: RCQM will immerse global visitors in cross-disciplinary research September 30th, 2014

Big Results Require Big Ambitions: Three young UCSB faculty receive CAREER awards from the National Science Foundation September 18th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE