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InTheLoop | 07.23.2007

The weekly newsletter for Berkeley Lab Computing Sciences

July 23, 2007

Berkeley Researchers Find New Way to Fabricate Striped Nanorods


A team of researchers from LBNL and UC Berkeley has found a way to make striped nanorods in a colloid, a suspension of particles in solution, according to a paper published in the July 13 issue of the journal Science. Using computational methods developed by scientists in the Computational Research Division, lead researcher Paul Alivisatos, an internationally recognized authority on colloidal nanocrystal research, demonstrated a new way to create a striped nanorod. The researchers performed their calculations on supercomputers at NERSC.

“We have demonstrated the application of strain engineering in a colloidal quantum-dot system by introducing a method that spontaneously creates a regularly spaced arrangement of quantum dots within a colloidal quantum rod,” Alivisatos said. “A linear array of quantum dots within a nanorod effectively creates a one-dimensional superlattice, or striped nanorod.”

Superlatticed or “striped" nanorods — crystalline materials only a few molecules in thickness and made up of two or more semiconductors — are highly valued for their potential to serve in a variety of nanodevices, including transistors, biochemical sensors and light-emitting diodes (LEDs). Until now the potential of superlatticed nanorods has been limited by the relatively expensive and exacting process required to make them. That paradigm may be shifting.

Previously, striped nanorods were made through epitaxial processes, in which the rods were attached to or embedded within a solid medium.

“This project has involved tight coordination between computer simulations and experiment, and the results obtained here would not have been possible to achieve without the contributions of our computational scientists, Denis Demchenko and Lin-Wang Wang,” Alivisatos said. “It is another clear example where we see that theoretical simulations are not just being used to explain materials growth after the fact, but are now an integral part of the materials design and creation process from the very start.”

Read the full news release at http://www.lbl.gov/Science-Articles/Archive/MSD-striped-nanorods.html.


Stillwater Supercomputing Founder to Give Talk on Tuesday, July 24


Theodore Omtzigt, who founded Stillwater Supercomputing Solutions in 2005, will give an overview of the company’s technology at 1:30 p.m. Tuesday, July 24, in the Bldg. 50F conference room (1647). The company is seeking to build a dataflow supercomputer or at least a cluster that leverages a dataflow-like programming model, according to host John Shalf. Stillwater Supercomputing was formed to offer supercomputing capabilities to small and medium sized organizations, the company’s Web site states. Smaller organizations do not have large IT operations, or sizable teams of support engineers, to make supercomputing facilities productive. For these companies, a supercomputer needs to be as simple to install, and as easy to operate, as a single workstation.


ESnet Workshop to Focus on Future Network Requirements for BER


ESnet is hosting a workshop on July 26-27. “The goal of this workshop is to accurately characterize the networking requirements of science funded by the BER (Biological and Environmental Research) Program Office. These requirements will serve as input to the ESnet architecture and planning processes, and will help ensure that ESnet continues to provide world-class support for scientific discovery for DOE scientists and their collaborators. The tangible outcome of the workshop will be a document that includes both the network requirements and a supporting narrative describing the science process underlying the network requirements,” according to the workshop Web site.

The by-invitation-only workshop is the second in a series, with the first held in June to examine networking requirements of the Basic Energy Sciences Program Office. The BER workshop is being held in North Bethesda, Md.



About Computing Sciences at Berkeley Lab

The Lawrence Berkeley National Laboratory (Berkeley Lab) Computing Sciences organization provides the computing and networking resources and expertise critical to advancing the Department of Energy's research missions: developing new energy sources, improving energy efficiency, developing new materials and increasing our understanding of ourselves, our world and our universe.

ESnet, the Energy Sciences Network, provides the high-bandwidth, reliable connections that link scientists at 40 DOE research sites to each other and to experimental facilities and supercomputing centers around the country. The National Energy Research Scientific Computing Center (NERSC) powers the discoveries of 6,000 scientists at national laboratories and universities, including those at Berkeley Lab's Computational Research Division (CRD). CRD conducts research and development in mathematical modeling and simulation, algorithm design, data storage, management and analysis, computer system architecture and high-performance software implementation. NERSC and ESnet are DOE Office of Science User Facilities.

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 DOE’s Office of Science.

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 science.energy.gov.