NIST Technicalendar August 18 to August 22, 2008 The NIST Technicalendar is issued each Friday. All items MUST be submitted electronically from this web page by 12:00 NOON each Wednesday unless otherwise stated in the NIST Technicalendar. The address for online weekly editions of the NIST Technicalendar and NIST Administrative Calendar is: http://www.nist.gov/tcal/.

In this Issue: Meetings at NIST Meetings Elsewhere Announcements Talks by NIST Personnel NIST Web Site Announcements NIST Administrative Calendar (current)   NIST Vacancy Announcements (current)

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10:30 AM - Studying Nanostructures with Light - Massively Parallel Characterization of Individual Carbon Nanotubes
2:00 PM - The Quest to Make NIST "Green"
2:00 PM - Semiconductor Two-Photon Emission

10:30 AM - The nonlinear and linear phenomena in silicon nanostructures
10:45 AM - A Guide to new Scientific Opportunities on HRPD at the ISIS Facility

No Scheduled Events

10:30 AM - Artificial Spin Ice

No Scheduled Events

8/18 -- MONDAY

10:30 AM - CNST NANOFABRICATION RESEARCH GROUP SEMINAR: Studying Nanostructures with Light - Massively Parallel Characterization of Individual Carbon Nanotubes
Nanostructures, including single molecules, carbon nanotubes and semiconductor nanowires often exhibit excellent characteristics that are comparable, and in some cases even superior, to the properties of traditional semiconductors. Their electrical and optical properties are determined by the complex interplay between multiple processes occurring in differing length and time scales. Exploring electrical and optical phenomena at this scale therefore requires a tool to investigate these complex, multi-scale processes at the system-wide level. In this talk, I will discuss our approach to investigate the coupling between electronic motion in 1D and 2D nanostructures (nanotubes, nanowires and single layer graphene) and various physical properties, including the electron band map, contact energy barriers, and electron phonon couplings. In particular, we recently developed a novel laser-based microscopy for addressing electrical conductance properties of a large number of individual nanostructures. We applied this technique to successfully characterize a large number of carbon nanotubes grown over a macroscopic area (~millimeters) with a high throughput ( 100/min). Our technique is an important step toward a real-time chemical imaging with which one can monitor electrical conductance change of an array of nanostructures while they are exposed to various chemical reactions.
Jiwoong Park , Department of Chemistry and Chemical Biology, Cornell University.
Bldg. 217, Rm. H107. (NIST Contact: James Liddles, 301-975-6050, james.liddle@nist.gov)

2:00 PM - BUILDING AND FIRE RESEARCH LABORATORY SEMINAR: The Quest to Make NIST "Green"
With the growing evidence of humans' effect on the atmosphere and the rising cost of fuel, the last several years have seen great emphasis placed on the environmental impacts of our actions. How does NIST rate in terms of environmental performance, and what are we doing to make NIST a more "Green" place? This seminar will discuss work undertaken by a team in NIST's New Leader Program that explored ways in which NIST is seeking to become a more environmentally-friendly workplace and will recommend further steps that we can take to make NIST a greener place.
Tom Cleary , Fire Research Division. Bill Healy , Building Environment Division.
Administration Bldg, Lecture Rm. B. (NIST Contact: Aaron Forster, 301-975-8701, aaron.forster@nist.gov)
Special Assistance Available

2:00 PM - OPTICAL TECHNOLOGY DIVISION SEMINAR: Semiconductor Two-Photon Emission
Alex Hayat , Israel Institute of Technology.
Radiation Physics Bldg, Rm. B105. (NIST Contact: Alan Migdall, 301-975-2331, alan.migdall@nist.gov)


8/19 -- TUESDAY

10:30 AM - CNST NANOFABRICATION RESEARCH GROUP SEMINAR: The nonlinear and linear phenomena in silicon nanostructures
Silicon photonics has attracted much attention recently because of its potential for providing a monolithically integrated platform for both linear and nonlinear applications. In this presentation, I'll talk about our recent result on the application of silicon photonics, in both linear and nonlinear regime, including the measurement of silicon's nonlinearities, the formation of optical solitons in a silicon waveguide and EO modulator based on silicon photonic crystal and novel EO polymer.
Jidong Zhang , Dept. of ECE, University of Rochester,.
Bldg. 217, Rm. H107. (NIST Contact: Vladimir Aksyuk, 301-975-2867, vladimir.aksyuk@nist.gov)

10:45 AM - NIST CENTER FOR NEUTRON RESEARCH SEMINAR: A Guide to new Scientific Opportunities on HRPD at the ISIS Facility
The on-going development of instrumentation at neutron facilities such as ISIS is crucial for optimal utilization of the source and to keep pace with the increasingly stringent demands of materials characterization in emerging fields in science and technology research. The high-resolution powder diffractometer, HRPD, at ISIS has been upgraded recently with the installation of a 100 m long high-reflectivity supermirror guide. Using modern optics concepts, such as ballistic and elliptical guides, coupled with advances in supermirror technology, the new guide has realized flux gains between 1 and 2 orders of magnitude compared with the original "day 1" guide installed on the instrument. The current design process benefits from extensive Monte Carlo simulations, which are used not only to verify the predictions of the theoretical models with more realistic components, but also to optimize some of the design parameters. At ISIS, we have implemented a grid-based Monte Carlo engine, which can produce Rietveld-refineable data from fully-realistic virtual instruments with complex primary-optics and detector geometries. Results of these simulations will be presented, together with the first real neutron data, for the upgraded HRPD. It will be shown that the flux gains from this unique curved elliptical guide are produced without significant loss of resolution or deterioration of the peak shapes in both simulations and real data. The new guide also transmits shorter wavelength neutrons that were previously cut off making it feasible to access even shorter d-spacings. Initial results collected during the recent technical and scientific commissioning programme will be presented demonstrating HRPD's improved performance. Opportunities for new science, using examples which compare new results with past highlights on HRPD in the field of molecular crystallography as well as more recent topical studies on hydrogen storage materials, will also be discussed.
Robert Ibberson , ISIS Facility--Rutherford Appleton Laboratory, UK. ,.
235 Bldg, Rm. E100. (NIST Contact: Rob Dimeo, 301-975-8135, robert.dimeo@nist.gov)


8/20 -- WEDNESDAY

No Scheduled Events

8/21 -- THURSDAY

10:30 AM - CNST ELECTRON PHYSICS GROUP SEMINAR: Artificial Spin Ice
Frustration arises from competition of pair-wise interactions such that not all of them can be satisfied simultaneously. It is thought to be ubiquitous and has been a topic of interest over half century. Particularly, spin ice in the Pyrochlore structure is a geometrically frustrated system which has a two-in, two-out spin configuration at each tetrahedron, mapping to the famous ice rule in water ice, thus could be used as a model material to study frustration, especially ice rule governed disorder. However, current experimental methods on Pyrochlore materials lack the ability to probe specific spins locally in experiments. More recently, researchers using nanolithography techniques demonstrated an approach called "artificial spin ice", a square lattice constructed from ferromagnetic nanoelements. The elements act as single spins and the square lattice were thought to analogous to spin ice on a 2D square lattice. This artificial approach is very attractive towards the goal to "see" local spins. However, an amount of vertices in this square lattice doesn't obey the ice rule, thus this square lattice doesn't show spin ice frustration. We explore this approach further by designing a kagome lattice, and we employ transmission electron microscope (TEM) imaging in Lorentz mode to detect the spin directions. The kagome spin ice lattice is a component of pyrochlore spin ice structure and which is a more frustrated in 2-D than square lattice. Based on this lattice, the frustration accommodating spin configuration, correlations, magnetic field induced dynamics, and the symmetry effects are studied. Results are shown and found consistent with nearest neighbor spin ice model. This work will contribute to further our knowledge about the physics of ice and frustration.
Yi Qi , Ph.D. Candidate, Dep. of Materials Science and Engineering, University of Maryland.
Bldg. 217, Rm. H107. (NIST Contact: John Unguris, 301-975-3712, John.Unguris@nist.gov)


8/22 -- FRIDAY

No Scheduled Events

ADVANCE NOTICE

8/29/08 1:30 PM - CNST ELECTRON PHYSICS GROUP SEMINAR: Cold Rydberg Atoms
Photo-excitation of atoms in laser-cooled gases allows the creation of gases of cold Rydberg atoms. In these gases at higher densities, rich dynamics stem from electric multipole interactions among the Rydberg atoms. For example, interatomic forces between Rydberg atoms cause state-changing collisions which can significantly increase the kinetic energy of the colliding atoms. I will discuss experiments examining these collisions in which internal energy of the Rydberg atoms is converted into kinetic energy. At lower densities, translationally cold Rydberg atoms are well-suited for spectroscopic studies to measure atomic properties. I will present a recently proposed scheme for driving transitions between Rydberg states via a time-dependent ponderomotive interaction between the Rydberg electron and an applied optical field and discuss experimental efforts to realize this new spectroscopic tool.
Brenton Knuffman , Ph.D. Candidate, University of Michigan, Ann Arbor, MI.
Bldg. 217, Rm. H107. (NIST Contact: Jabez McClelland, 301-975-3721, Jabez.McClelland@nist.gov)

9/5/08 10:30 AM - NIST COLLOQUIUM SERIES: The Physics of Music and the Music of Quantum Physics
Rolling ripples of water on the surface of a pond, the brilliant colors of a deep rainbow, and Beethoven's symphonies all come to us in the form of waves. While we all appreciate the beauty of these experiences in life without caring about the underlying physics, they become even more beautiful when we dive into their simple physical and mathematical description. This lecture will explore the generation of sound, what makes sound into music, and how we perceive complex sound waves. An attempt will be made to connect music to a different sort of wave physics that appears at the atomic scale: quantum mechanics. While it is difficult to experience quantum waves in the same way as music, there are many interesting analogies between the two, involving measurement, perception, and superposition.
Christopher Monroe , Joint Quantum Institute, University of Maryland Physics Department and NIST.
Administration Building, Green Auditorium. (NIST Contact: Kum Ham, 301-975-4203, kham@nist.gov)
Special Assistance Available

9/15/08 1:30 PM - CNST NANOFABRICATION RESEARCH GROUP SEMINAR: Andreev current induced dissipation in a Superconductor – Normal metal – Superconductor tunnel junction
In the recent years, nano-refrigeration using electron tunneling in hybrid Normal metal - Insulator - Superconductor (N-I-S) junctions has gained increasing attention [1]. Its basic principle is the energy selective tunneling due to the presence of an energy gap in the superconductor density of states. With a sub-gap voltage bias, only the most energetic electrons can tunnel out of the normal metal, leaving behind the electrons with less energy. We have measured with a high resolution the differential conductance of S-I-N-I-S junctions, whose analysis gives us an access to the normal metal electronic temperature as a function of the voltage. A quantitative model is proposed, that includes the electron-phonon coupling and the Kapitza resistance at the interface with the substrate. With this model, we have achieved a thorough description of the charge and heat currents [2]. We have also shown that the normal metal phonon temperature drops significantly below the substrate temperature. At very low temperature (T 200mK) and low bias, the phase coherent Andreev current dominates the quasi-particle current. By analyzing quantitatively the heat balance in the S-I-N-I-S junction, we demonstrate that the Andreev current does carry heat. This thermal contribution heats the normal metal electrons, overriding over a large voltage range the tunneling-based cooling [3].
Sukumar Rajauria , Néel Institute, CNRS and Université Joseph Fourier.
Bldg. 217, Rm. H107. (NIST Contact: James Liddle, 301-975-6050, james.liddle@nist.gov)

9/16/08 10:30 AM - CNST ELECTRON PHYSICS GROUP SEMINAR: Towards quantum information processing using single neutral atoms
To realize quantum information processing with neutral atoms, controlled coherent interaction between them is a fundamental requirement. One approach relies on deterministic coupling of two or more atoms to the mode of a high-finesse optical resonator in the strong coupling regime. We investigate such a coupling between neutral atoms and a resonator under controlled conditions: we load a chosen number of Doppler-cooled caesium atoms from a magneto-optical trap into a standing wave optical dipole trap. The positions of the individual atoms are then determined with sub-micrometer precision, enabling us to prepare, to manipulate and to read out the quantum state of each atom. Using the dipole trap as an optical conveyor belt, the atoms are transported into the mode of a high-finesse optical cavity with a finesse of F=106, leading to a maximum single-atom cooperativity parameter of the order of 50. By observing the transmission of a weak resonant probe laser we can detect the interaction dynamics of a single atom coupled strongly to the cavity field. Cooling by the probe laser extends the observation time to several ten seconds, allowing us to investigate the strength and the stability of coupling, which are crucial parameters for the controlled coherent interaction. Moreover, we analyze the atom-field interaction using a method, essential for the creation and measurement of entanglement.
Mkrtych Khudaverdyan , Ph.D. Student/Institute of Applied Physics, Bonn, Germany.
Bldg. 217, Rm. H107. (NIST Contact: Jabez McClelland, 301-975-3721, Jabez.McClelland@nist.gov)

9/16/08 10:30 AM - ATOMIC PHYSICS DIVISION SEMINAR: Carbon-nanotube field-effect transistors as chemical sensors
Single-walled carbon nanotubes are seamless molecular cylinders that are either metallic or semiconducting nanowires. The conductance of a semiconducting nanotube can be tuned by applying a voltage to a nearby gate electrode, providing a one-dimensional field-effect transistor at the nanometer scale. These transistors are very sensitive detectors: Their electrical properties vary strongly when they are exposed to chemicals. After the first experiments seven years ago, where high sensitivity to NH3 (monitored in farms and industries) and NO2 (an air pollutant from motor vehicle exhaust and other combustion sources) was discovered [1], a strong sensitivity to many other molecules, including oxygen, methane, alcohol vapor and proteins, has also been reported. The cause of the change in electrical properties is still unclear. One possibility is that molecules bind to the surface of the nanotubes and charge transfer occurs between the nanotube and the molecules. A second possibility is a change of the barriers for electrical transport at the interface between the nanotube and the electrical contacts. Understanding the mechanism that causes the response to each chemical is an essential step for the design of efficient sensors. I will discuss an experimental method we recently developed to determine the sensing mechanism. We find that, in the case of NO2, sensing occurs through the contacts [2]. [1] J. Kong, N. R. Franklin, C. Zhou, M. G. Chapline, S. Peng, K. Cho, and H. Dai, Science 287, 622 (2000). [2] J. Zhang, A. Boyd, A. Tselev, M. Paranjape, and P. Barbara, Appl. Phys. Lett. 88, 123112 (2006).
Paola Barbara , Physics Department, Georgetown University.
Physics Building, Room B145. (NIST Contact: Neil Zimmerman, 301-975-5887, neil.zimmerman@nist.gov)

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MEETINGS ELSEWHERE


8/18 -- MONDAY

No Scheduled Events

8/19 -- TUESDAY

No Scheduled Events

8/20 -- WEDNESDAY

No Scheduled Events

8/21 -- THURSDAY

No Scheduled Events

8/22 -- FRIDAY

No Scheduled Events

ADVANCE NOTICE

No Scheduled Events

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TALKS BY NIST PERSONNEL

HOLBROOK, D. : SENSITIVITY ANALYSIS OF CNT COAGULATION IN AQUATIC ENVIRONMENTS.
American Chemical Society 236th National Meeting & Exposition, Philadelphia, PA, 8/17.

HAYAT, A. "Semiconductor Two-Photon Emission" 2:00 p.m. Radiation Physics Room B105 Gaithersburg, MD 20899, 8/18.

CHAKA, A. : FIRST-PRINCIPLES CHARACTERIZATION OF KEY FACTORS IN POLLUTANT OXIDE-WATER INTERFACES.
236th National ACS (American Chemical Society) Meeting, Philadelphia Conference Center, Philadelphia PA, 8/18.

MASON, S. : FIRST-PRINCIPLES CHARACTERIZATION OF KEY FACTORS IN POLLUTANT OXIDE-WATER INTERFACES.
236th National ACS (American Chemical Society) Meeting, Philadelphia Conference Center, Philadelphia PA, 8/18.

CLARK, C. : MATTER WAVE MAGIC.
Naval Air Systems Command, Patuxent River Naval Air Station, MD, 8/18.

KARIM, A. : INTERACTIONS OF NANOPARTICLES WITH BLOOD PLASMA PROTEINS.
American Chemical Society Meeting, Philadelphia, PA, 8/18.

MICHAELS, C. : INFRARED CHEMICAL IMAGING WITH A SOLID IMMERSION LENS.
American Chemical Society 236th National Meeting & Exposition, Philadelphia, PA, 8/19.

WINDSOR, E. : USE OF DROP ON DEMAND INKJET PRINTING TECHNOLOGY TO PRODUCE REFERENCE MATERIALS FOR TRACE LEVEL EXPLOSIVE ANALYSIS.
Americal Chemical Society Conference, Philadelphia, PA, 8/19.

WHITE V, E. : INTRODUCTION TO AMDIS.
Food Emergency Response Network (FERN), Cincinnati, OH, 8/19.

BECKER, M. (Co-Authors: J.Fagan , N.Gallant ) Bauer, B. J. ; Hobbie, E. K. ; Lacerda, S. H. ; Migler, K.B. : LENGTH DEPENDENT UPTAKE OF SINGLE WALL CARBON NANOTUBES.
American Chemical Society (ACS), Philadelphia, PA, 8/19.

HOLBROOK, D. : BEHAVIOR OF ENGINEERED NANOPARTICLES IN AQUATIC SYSTEMS - AN OVERVIEW.
American Chemical Society 236th National Meeting & Exposition, Philadelphia, PA, 8/19.

GERGEL-HACKETT, N. (Co-Authors: A.A.Hill , ah3@umbc.edu I.N.Aquilar , aquilar1@umbc.edu) Hacker, C.A; Richter, C.A; : THE INTEGRATION OF MOLECULAR ELECTRONIC DEVICES WITH TRADITIONAL CMOS TECHNOLOGIES.
IEEE Nano 2008, Arlington, TX, 8/20.

GERMACK, D. : VERTICAL COMPOSITION GRADIENTS IN ORGANIC BULK HETEROJUNCTION SOLAR CELLS.
American Chemical Society National Meeting, Philadelphia, PA, 8/21.

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ANNOUNCEMENTS

2008 WORLD STANDARDS DAY PAPER COMPETITION
The U.S. standards community will celebrate World Standards Day on Thursday, October 23, 2008, at the Ronald Reagan Building and International Trade Center in Washington, DC. The theme for this year's celebration, "Intelligent and Sustainable Buildings," recognizes the critical role of standards and conformity assessment programs in ensuring safety requirements; facilitating coordination among contractors, builders, engineers, and architects; and incorporating new technologies in design and construction. In conjunction with this year's event, the 2008 World Standards Day sponsors, including NIST will hold the annual paper competition. The 2008 World Standards Day Paper Competition invites papers that use specific examples to show ways that standards and conformity assessment programs are used for intelligent and sustainable buildings. Paper competition winners will be announced and given their awards at the US celebration of World Standards Day. The first place winner will receive a plaque and $2,500. Second and third place winners will receive $1,000 and $500, respectively, along with a certificate. In addition, the winning papers will be published in SES's journal, "Standards Engineering." ELIGIBILITY: The competition is open to U.S.-based individuals in the private sector, government, or academia. Papers may be co-authored. RULES: Entries must be original and not previously published. NIST papers must be processed through WERB or BERB. All paper contest submissions must be received with an official entry form by midnight on August 29, 2008, by the SES Executive Director, 13340 SW 96th Avenue, Miami, Florida, 33176. Complete details and official entry forms are available on the SES website www.ses-standards.org (follow the link for "2008 WSD Paper Competition.") For additional information about the U.S. Celebration of World Standards Day, or to register for the event, please visit www.wsd-us.org.
NIST Contact: Mary Donaldson, 301-975-6197, mary.donaldson@nist.gov

HOW CAN YOUR LAB LIAISON HELP YOU?
Watch this new video podcast and learn what NIST Labs are saying about ISD's Lab Liaisons. (4+ minutes) http://nvl-i.nist.gov/docs/videos/ISD_liaisons/
NIST Contact: Information Desk, 301-975-3052, library@nist.gov

VISITOR REGISTRATION FOR NIST EVENTS
Because of heightened security at the NIST Gaithersburg site, members of the public who wish to attend meetings, seminars, lectures, etc. must first register in advance. For more information please call or e-mail the "NIST Contact" for the particular event you would like to attend.
NIST Contact: . ., ., .

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NIST WEB SITE ANNOUNCEMENTS

No Web Site announcements this week.

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For more information, contact Ms. Sharon Hallman, Editor, Stop 2500, National Institute of Standards and Technology, Gaithersburg MD 20899-2500; Telephone: 301-975-TCAL (3570); Fax: 301-926-4431; or Email: tcal@nist.gov.

All lectures and meetings are open unless otherwise stated.

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