Exploring the Exotic World of Nanomaterials

By Paul Tooby

February 10, 2006

In the tiny world of nanomaterials — smaller than the wavelength of visible light — strange new materials can exhibit unexpected behavior and properties, not at all what we would expect from our experience in the larger scale of everyday life. And because they behave in novel ways, researchers are excited about the potential applications of these new materials to make dramatic improvements in technologies from electronics to medical diagnostics.

For example, nanoelectronic devices may offer vastly-expanded data storage capabilities with reduced power consumption, and a newly-discovered nanoscale device, described below, emits body-penetrating infrared light that could one day improve medical diagnosis.

The research groups of physics professors Marvin Cohen and Steven Louie at UC Berkeley collaborate on investigations in which they use supercomputers at the San Diego Supercomputer Center at UC San Diego as a key part of their computational physics research. They combine this with theoretical approaches in which they aim both to explain the properties and behavior of nanoscale materials and also to predict entirely new materials and phenomena never seen before.

Nanomaterials are a very dynamic area of research, with exciting discoveries from buckyballs to nanotubes emerging in recent years through collaborative efforts among theoretical, computational, and experimental researchers. In this creative research environment, the Berkeley scientists find that computational science is an essential tool, sometimes responding to experimental and theoretical advances, and at times leading and identifying novel materials and phenomena. “Our ab initio simulations model materials from first principles,” said Professor Cohen of UC Berkeley. “These realistic simulations, which can yield discoveries of materials and properties never seen before, are very computationally intensive, requiring the large, data-oriented resources that SDSC provides.”

Nanopeapods and Buckyballs

To explore nanomaterials in a number of areas, the Cohen and Louie groups received a combined allocation of some 1.3 million processor hours on DataStar. Processor-hours refers to how time is allocated on a supercomputer. A project with a one million hour allocation could run on 1,000 processors of a parallel machine for 1,000 hours, or about 42 days. Running the same project on a single-processor computer would take more than 115 years!

One class of inhabitants of the exotic nanoworld the researchers are exploring is known as “nanopeapods,” in which carbon or boron-nitride nanotubes have the intriguing ability to encapsulate other chemical species. In nanopeapods, or functionalized nanotubes, the details of the position of guest atoms within the cage-like structure are of great interest to materials scientists because they affect electronic and other properties of these systems.

The researchers studied the electronic and geometrical structure of boron nitride and carbon nanotubes in encapsulating the C60 molecules known as buckyballs. Using ab initio calculations with the PARATEC and SIESTA codes, they performed self-consistent density functional theory computations. The structural complexity of nanopeapods means that a very large number of atoms had to be included in the simulation cell, requiring major computational resources. In the nanopeapods, the researchers found that the buckyball “peas” added new features to the electronic structure of the host nanotube, resulting in changes in the electronic transport properties that may prove useful in molecular-scale electronic devices.

The Cohen and Louie groups have also studied other nanoscale electronic devices using first-principles calculations of electron transport. These simulations used a scattering-state code that the researchers developed to calculate the electrical current in these molecules and nanostructures as a function of bias voltage. One motivation for this research, in addition to learning more about the fundamental science, is eventually to be able to extend Moore's law for ever-faster computing devices by developing devices that are smaller, more energy-efficient, and faster to overcome the limitations to further shrinking silicon-based semiconductors.

Simulating electron transport through single-molecule devices, the researchers explored behavior suggested by experiments in which resistance in the nanoscale devices can sometimes unexpectedly decrease. This is in striking contrast to “normal” behavior in bulk metal wires, where resistance increases as bias voltage increases. This nonlinear behavior is exciting to physicists and electrical engineers because it holds out the promise of new electronics applications.

Light-emitting Nanotubes

Yet another area of research involves the optical properties of nanotubes. It turns out that carbon nanotubes can emit light in the infrared range. The researchers have simulated this behavior in the one-dimensional world of nanotube semiconductors, where the excitons, or electron-hole pairs, are very strongly bound. “With the help of SDSC resources, we were able to make the exciting discovery of a giant excitonic effect in the optical response of the nanotubes,” said Professor Steven Louie of UC Berkeley. “This effect is orders of magnitude larger than what is found in standard semiconductors such as silicon.” The ability to emit infrared light with strikingly different optical properties than in bulk material has potential applications in such areas as medical diagnosis, since infrared light can penetrate the human body.

The researchers computed the optical properties from first principles in three steps using three codes, two running on 64 processors in runs of up to 1,500 hours and the final step computing on as many as 640 processors in runs of 24 hours. The computationally most burdensome parts of these codes involve the algebraic manipulation of very large matrices, as well as Fast Fourier Transforms. The data-oriented resources of SDSC were vital to their research, the scientists explained, because of the very large computational requirements, the large memory requirements, and especially the need for very fast data communication between nodes that is provided by DataStar.

Nanoscale Superconductivity and Friction

Another area the researchers explored is superconductivity in novel materials. By building new structures not found in nature such as boron nitride nanotubes containing C60 molecules and potassium, new electrical properties including superconductivity can emerge. By simulating these structures, the researchers are gaining insights into the basic physics taking place, which they hope can eventually lead to higher-temperature superconducting materials with major technological applications such as more-efficient electricity transmission.

Finally, the wide-ranging research of the Cohen and Louie groups used SDSC resources to explore friction at the nanoscale. This is important in the development of nanomachines such as tiny motors. The simulations are helping answer questions related to how mechanical energy is dissipated at these small scales, with properties that differ greatly from what is observed at the scale of bulk materials we experience in everyday life. For these simulations, the researchers used classical molecular dynamics simulations of tens of thousands of atoms.

Related Links:
Cohen research group – http://civet.berkeley.edu/cohen/
Louie research group – http://tiger.berkeley.edu/louie/index.htm
SDSC User Services – http://www.sdsc.edu/user_services/
SDSC Allocations – http://www.sdsc.edu/user_services/allocations/

This article was provided courtesy of the San Diego Supercomputing Center.

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industy updates delivered to you every week!

At SC19: What Is UrgentHPC and Why Is It Needed?

November 14, 2019

The UrgentHPC workshop, taking place Sunday (Nov. 17) at SC19, is focused on using HPC and real-time data for urgent decision making in response to disasters such as wildfires, flooding, health emergencies, and accidents. We chat with organizer Nick Brown, research fellow at EPCC, University of Edinburgh, to learn more. Read more…

By Tiffany Trader

China’s Tencent Server Design Will Use AMD Rome

November 13, 2019

Tencent, the Chinese cloud giant, said it would use AMD’s newest Epyc processor in its internally-designed server. The design win adds further momentum to AMD’s bid to erode rival Intel Corp.’s dominance of the glo Read more…

By George Leopold

NCSA Industry Conference Recap – Part 1

November 13, 2019

Industry Program Director Brendan McGinty welcomed guests to the annual National Center for Supercomputing Applications (NCSA) Industry Conference, October 8-10, on the University of Illinois campus in Urbana (UIUC). One hundred seventy from 40 organizations attended the invitation-only, two-day event. Read more…

By Elizabeth Leake, STEM-Trek

Cray, Fujitsu Both Bringing Fujitsu A64FX-based Supercomputers to Market in 2020

November 12, 2019

The number of top-tier HPC systems makers has shrunk due to a steady march of M&A activity, but there is increased diversity and choice of processing components with Intel Xeon, AMD Epyc, IBM Power, and Arm server ch Read more…

By Tiffany Trader

Intel AI Summit: New ‘Keem Bay’ Edge VPU, AI Product Roadmap

November 12, 2019

At its AI Summit today in San Francisco, Intel touted a raft of AI training and inference hardware for deployments ranging from cloud to edge and designed to support organizations at various points of their AI journeys. The company revealed its Movidius Myriad Vision Processing Unit (VPU)... Read more…

By Doug Black

AWS Solution Channel

Making High Performance Computing Affordable and Accessible for Small and Medium Businesses with HPC on AWS

High performance computing (HPC) brings a powerful set of tools to a broad range of industries, helping to drive innovation and boost revenue in finance, genomics, oil and gas extraction, and other fields. Read more…

IBM Accelerated Insights

Help HPC Work Smarter and Accelerate Time to Insight

 

[Attend the IBM LSF & HPC User Group Meeting at SC19 in Denver on November 19]

To recklessly misquote Jane Austen, it is a truth, universally acknowledged, that a company in possession of a highly complex problem must be in want of a massive technical computing cluster. Read more…

SIA Recognizes Robert Dennard with 2019 Noyce Award

November 12, 2019

If you don’t know what Dennard Scaling is, the chances are strong you don’t labor in electronics. Robert Dennard, longtime IBM researcher, inventor of the DRAM and the fellow for whom Dennard Scaling was named, is th Read more…

By John Russell

Cray, Fujitsu Both Bringing Fujitsu A64FX-based Supercomputers to Market in 2020

November 12, 2019

The number of top-tier HPC systems makers has shrunk due to a steady march of M&A activity, but there is increased diversity and choice of processing compon Read more…

By Tiffany Trader

Intel AI Summit: New ‘Keem Bay’ Edge VPU, AI Product Roadmap

November 12, 2019

At its AI Summit today in San Francisco, Intel touted a raft of AI training and inference hardware for deployments ranging from cloud to edge and designed to support organizations at various points of their AI journeys. The company revealed its Movidius Myriad Vision Processing Unit (VPU)... Read more…

By Doug Black

IBM Adds Support for Ion Trap Quantum Technology to Qiskit

November 11, 2019

After years of percolating in the shadow of quantum computing research based on superconducting semiconductors – think IBM, Rigetti, Google, and D-Wave (quant Read more…

By John Russell

Tackling HPC’s Memory and I/O Bottlenecks with On-Node, Non-Volatile RAM

November 8, 2019

On-node, non-volatile memory (NVRAM) is a game-changing technology that can remove many I/O and memory bottlenecks and provide a key enabler for exascale. That’s the conclusion drawn by the scientists and researchers of Europe’s NEXTGenIO project, an initiative funded by the European Commission’s Horizon 2020 program to explore this new... Read more…

By Jan Rowell

MLPerf Releases First Inference Benchmark Results; Nvidia Touts its Showing

November 6, 2019

MLPerf.org, the young AI-benchmarking consortium, today issued the first round of results for its inference test suite. Among organizations with submissions wer Read more…

By John Russell

Azure Cloud First with AMD Epyc Rome Processors

November 6, 2019

At Ignite 2019 this week, Microsoft's Azure cloud team and AMD announced an expansion of their partnership that began in 2017 when Azure debuted Epyc-backed instances for storage workloads. The fourth-generation Azure D-series and E-series virtual machines previewed at the Rome launch in August are now generally available. Read more…

By Tiffany Trader

Nvidia Launches Credit Card-Sized 21 TOPS Jetson System for Edge Devices

November 6, 2019

Nvidia has launched a new addition to its Jetson product line: a credit card-sized (70x45mm) form factor delivering up to 21 trillion operations/second (TOPS) o Read more…

By Doug Black

In Memoriam: Steve Tuecke, Globus Co-founder

November 4, 2019

HPCwire is deeply saddened to report that Steve Tuecke, longtime scientist at Argonne National Lab and University of Chicago, has passed away at age 52. Tuecke Read more…

By Tiffany Trader

Supercomputer-Powered AI Tackles a Key Fusion Energy Challenge

August 7, 2019

Fusion energy is the Holy Grail of the energy world: low-radioactivity, low-waste, zero-carbon, high-output nuclear power that can run on hydrogen or lithium. T Read more…

By Oliver Peckham

Using AI to Solve One of the Most Prevailing Problems in CFD

October 17, 2019

How can artificial intelligence (AI) and high-performance computing (HPC) solve mesh generation, one of the most commonly referenced problems in computational engineering? A new study has set out to answer this question and create an industry-first AI-mesh application... Read more…

By James Sharpe

Cray Wins NNSA-Livermore ‘El Capitan’ Exascale Contract

August 13, 2019

Cray has won the bid to build the first exascale supercomputer for the National Nuclear Security Administration (NNSA) and Lawrence Livermore National Laborator Read more…

By Tiffany Trader

DARPA Looks to Propel Parallelism

September 4, 2019

As Moore’s law runs out of steam, new programming approaches are being pursued with the goal of greater hardware performance with less coding. The Defense Advanced Projects Research Agency is launching a new programming effort aimed at leveraging the benefits of massive distributed parallelism with less sweat. Read more…

By George Leopold

AMD Launches Epyc Rome, First 7nm CPU

August 8, 2019

From a gala event at the Palace of Fine Arts in San Francisco yesterday (Aug. 7), AMD launched its second-generation Epyc Rome x86 chips, based on its 7nm proce Read more…

By Tiffany Trader

D-Wave’s Path to 5000 Qubits; Google’s Quantum Supremacy Claim

September 24, 2019

On the heels of IBM’s quantum news last week come two more quantum items. D-Wave Systems today announced the name of its forthcoming 5000-qubit system, Advantage (yes the name choice isn’t serendipity), at its user conference being held this week in Newport, RI. Read more…

By John Russell

Ayar Labs to Demo Photonics Chiplet in FPGA Package at Hot Chips

August 19, 2019

Silicon startup Ayar Labs continues to gain momentum with its DARPA-backed optical chiplet technology that puts advanced electronics and optics on the same chip Read more…

By Tiffany Trader

Crystal Ball Gazing: IBM’s Vision for the Future of Computing

October 14, 2019

Dario Gil, IBM’s relatively new director of research, painted a intriguing portrait of the future of computing along with a rough idea of how IBM thinks we’ Read more…

By John Russell

Leading Solution Providers

ISC 2019 Virtual Booth Video Tour

CRAY
CRAY
DDN
DDN
DELL EMC
DELL EMC
GOOGLE
GOOGLE
ONE STOP SYSTEMS
ONE STOP SYSTEMS
PANASAS
PANASAS
VERNE GLOBAL
VERNE GLOBAL

Intel Confirms Retreat on Omni-Path

August 1, 2019

Intel Corp.’s plans to make a big splash in the network fabric market for linking HPC and other workloads has apparently belly-flopped. The chipmaker confirmed to us the outlines of an earlier report by the website CRN that it has jettisoned plans for a second-generation version of its Omni-Path interconnect... Read more…

By Staff report

Kubernetes, Containers and HPC

September 19, 2019

Software containers and Kubernetes are important tools for building, deploying, running and managing modern enterprise applications at scale and delivering enterprise software faster and more reliably to the end user — while using resources more efficiently and reducing costs. Read more…

By Daniel Gruber, Burak Yenier and Wolfgang Gentzsch, UberCloud

Dell Ramps Up HPC Testing of AMD Rome Processors

October 21, 2019

Dell Technologies is wading deeper into the AMD-based systems market with a growing evaluation program for the latest Epyc (Rome) microprocessors from AMD. In a Read more…

By John Russell

Rise of NIH’s Biowulf Mirrors the Rise of Computational Biology

July 29, 2019

The story of NIH’s supercomputer Biowulf is fascinating, important, and in many ways representative of the transformation of life sciences and biomedical res Read more…

By John Russell

Xilinx vs. Intel: FPGA Market Leaders Launch Server Accelerator Cards

August 6, 2019

The two FPGA market leaders, Intel and Xilinx, both announced new accelerator cards this week designed to handle specialized, compute-intensive workloads and un Read more…

By Doug Black

When Dense Matrix Representations Beat Sparse

September 9, 2019

In our world filled with unintended consequences, it turns out that saving memory space to help deal with GPU limitations, knowing it introduces performance pen Read more…

By James Reinders

With the Help of HPC, Astronomers Prepare to Deflect a Real Asteroid

September 26, 2019

For years, NASA has been running simulations of asteroid impacts to understand the risks (and likelihoods) of asteroids colliding with Earth. Now, NASA and the European Space Agency (ESA) are preparing for the next, crucial step in planetary defense against asteroid impacts: physically deflecting a real asteroid. Read more…

By Oliver Peckham

Cerebras to Supply DOE with Wafer-Scale AI Supercomputing Technology

September 17, 2019

Cerebras Systems, which debuted its wafer-scale AI silicon at Hot Chips last month, has entered into a multi-year partnership with Argonne National Laboratory and Lawrence Livermore National Laboratory as part of a larger collaboration with the U.S. Department of Energy... Read more…

By Tiffany Trader

  • arrow
  • Click Here for More Headlines
  • arrow
Do NOT follow this link or you will be banned from the site!
Share This