NIST Technicalendar September 1 to September 5, 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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No Scheduled Events

10:30 AM - Semiconductor Quantum Dots, Synthesis and Applications

10:30 AM - Printable Polymer Devices for Plastic Electronics

10:30 AM - Interfacial Force Microscopy: How it Works, Its Application to the Study of Nanomechanical Properties and the Need for Sensor Calibration!

10:30 AM - The Physics of Music and the Music of Quantum Physics

9/1 -- MONDAY

No Scheduled Events

9/2 -- TUESDAY

10:30 AM - CNST NANOFABRICATION RESEARCH GROUP SEMINAR: Semiconductor Quantum Dots, Synthesis and Applications
Colloidal semiconductor nanoparticles with nearly perfect crystalline structure have unique optoelectronic properties, such as high quantum efficiency, tunable emission wavelength determined by particle size or elemental ratio of materials to make them, narrow emission and broad absorption profiles, and flexible surface configurations. These properties promise many attractive applications, such as high quality biological probes, high efficient emissive layer in LEDs, and next generation active layer in Photovoltaics. This presentation will discuss the synthesizing of a specific semiconductor quantum dots, alloyed quantum dots through wet chemistry approach, and more importantly, their applications in life science and optoelectronic devices.
Lianhua Qu, PhD , Chief Scientific Officer, Crystalplex Corporation,. ,.
Bldg. 217, Rm. H107. (NIST Contact: Nikolai Zhitenev, 301-975-6039, nikolai.zhitenev@nist.gov)


9/3 -- WEDNESDAY

10:30 AM - CNST NANOFABRICATION RESEARCH GROUP SEMINAR: Printable Polymer Devices for Plastic Electronics
Semiconducting polymeric optoelectronic and electronics devices have evolved as promising cost-effective alternative to silicon-based devices. These devices include light emitting diodes (LED), thin film transistors, photovoltaic cells, lasers, and sensors. In this presentation, I will summarize our recent progress on: (1) single- and multi-layer white light LED fabricated by solution processing of each layer from semiconducting polymers; (2) performance of bulk heterojunction polymer solar cells. Polymer solar cells with post-production treatment and polymer solar cells with optical spacer exhibit enhanced power conversion efficiencies compared to similar devices without post-production treatment and the devices without optical spacer; (3) polymer photodetector with spectral response up to 1400nm. The performance of polymer photodetector is comparable to or even better than their inorganic counterparts.
Xiong Gong , University of California at Santa Barbara,. ,.
Bldg. 217, Rm. H107. (NIST Contact: Nikolai Zhitenev, 301-975-6039, nikolai.zhitenev@nist.gov)


9/4 -- THURSDAY

10:30 AM - CERAMICS DIVISION SEMINAR: Interfacial Force Microscopy: How it Works, Its Application to the Study of Nanomechanical Properties and the Need for Sensor Calibration!
In this presentation, I will first discuss in detail the workings of Interfacial Force Microscopy (IFM), a typical scanning-probe technique distinguished by the use of a stable, force-feedback sensor. I will then illustrate its advantages by showing several applications to measurements of the local mechanical properties of materials. These studies include the role of steps in dislocation initiation in single-crystal Au, the rather strange mechanical properties of water confined at the nanometer level between hydrophilic surfaces, and the results of an application aimed at demonstrating the capability of measuring the local viscoelastic properties of polymers by using a classic example of a material that is often referred to as a "solid liquid". In the second portion of the talk, I will outline the development of the second-generation, two-dimensional laser interferometer IFM and briefly discuss an important application and the resultant need for a SI-traceable force standard at the micronewton level.
J.E. Houston , Sandia National Laboratories.
Materials Building, Rm. B307. (NIST Contact: Douglas Smith, 301-975-5768, douglas.smith@nist.gov)


9/5 -- FRIDAY

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


ADVANCE NOTICE

9/11/08 10:30 AM - CNST NANOFABRICATION RESEARCH GROUP SEMINAR: Nanoparticles with key-lock interactions: from self-assembly to drug delivery
By decorating colloidal particles and other nano-objects with various biomolecules, one can introduce highly selective key-lock interactions between them. This leads to a new class of systems and problems in soft condensed matter physics. In my talk, I will review a number of theoretical possibilities and recent experimental achievements in this new field. First, I will discuss DNA-mediated self-assembly of nanostructures and nanoclusters. The specificity and tunability of the interactions result in a remarkable morphological diversity of in such systems. In some of the proposed schemes, DNA can be used to essentially "program" the self-assembly of a desired structure. The colloids with type-dependent interactions can also be used for experimental realization of one of the simplest self-replicating system. Its study may shed some light onto such important problems as prebiotic evolution and origin of life. Finally, I will discuss how cooperative key-lock binding can be also utilized to dramatically enhance cell specificity of drug delivery, e.g. in cancer treatment.
Alexei Tkachenko , Physics Department, University of Michigan,.
Bldg. 217, Rm. H107. (NIST Contact: James Liddle, 301-975-6050, james.liddle@nist.gov)

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)

9/18/08 11:00 AM - MATERIALS SCIENCE AND ENGINEERING LABORATORY LECTURE SERIES: Electrical Methods for Measuring Mechanical Response of Thin Films
The nanoscale thin films of copper, aluminum, and other materials used as interconnects in semiconductor devices to conduct electrical power, signals, and heat are difficult to manufacture and are potential failure points in operation of the chips, particularly as these features shrink in size and must carry greater electrical and thermal loads. To better measure the mechanical and thermal-mechanical response of interconnects under these demanding conditions, we are developing electrical tests to assess strengths and thermal fatigue lifetimes. This approach allows us to test structures with very fine dimensions as well as those that are buried beneath other layers, without special specimen preparation, i.e. we test in the as-manufactured state. We use four-point probe methods and apply low frequency, high density alternating currents to effect controlled joule heating. Mechanical strains are then induced in the films due to the differences in coefficients of thermal expansion between the film and surrounding materials. Details of the methods as applied to copper and aluminum interconnects will be described, including observations of the evolution of microstructure with progressing damage, as determined by electron microscopy. This work was conducted by Nicholas Barbosa, Roy Geiss, David Read, and Robert Keller of the Materials Reliability Division, Nanoscale Reliability Group. VTC to Boulder in Building 2, Room 0113 at 9am MT
Robert Keller , Materials Research Engineer; Boulder, CO, keller@boulder.nist.gov.
Administration Bldg, Green Auditorium. (NIST Contact: Bill Boettinger, 301-975-6160, william.boettinger)

10/20/08 8:00 AM - CHEMICAL SCIENCE AND TECHNOLOGY LABORATORY OFFICE SEMINAR: "Accelerating Innovation in 21st Century Biosciences: Identifying the Measurement Standards and Technological Challenges"
The National Institute of Standards and Technology (NIST) and the University of Maryland Biotechnology Institute (UMBI) are planning to co-host an October 20-24, 2008 Conference (Symposium and Workshop) focused on identifying and prioritizing measurement, standards, and technology needs that represent barriers to innovation, and impediments to achieving maximal societal and economic benefits of new discoveries in the biosciences.
Invited Speakers , Various Organizations.
Administration Bldg, Red Auditorium. (NIST Contact: Willie May, 301-975-8300, wem@nist.gov) http://www.cstl.nist.gov/Biosciences.html
Special Assistance Available

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MEETINGS ELSEWHERE


9/1 -- MONDAY

No Scheduled Events

9/2 -- TUESDAY

No Scheduled Events

9/3 -- WEDNESDAY

No Scheduled Events

9/4 -- THURSDAY

No Scheduled Events

9/5 -- FRIDAY

No Scheduled Events

ADVANCE NOTICE

No Scheduled Events

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TALKS BY NIST PERSONNEL

SHULL, R. (Co-Authors: V.Provenzano A.J.Shapiro ) Zhang, T.B. : EFFECT OF SN ADDITION TO THE GIANT MAGNETOCALORIC EFFECTS OF GD5GE2SI2.
1st International Conference on Superconductivity and Magnetism, Side, Turkey, 8/29.

AMELOT, J. : EMBEDDED SENSOR DATA ACQUISITION AND TIME-STAMPING.
ESIAL, Nancy, France, 9/5.

LE GUEN, J. : SENSOR DATA FUSION FOR MULTILATERATION.
ESIAL, Nancy, France, 9/5.

RAMPANT, M. : MEASUREMENT DATABASE SYSTEMS FOR STANDARDS.
ESIAL, Nancy, France, 9/5.

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ANNOUNCEMENTS

HOW CAN YOUR LAB LIAISON HELP YOU?
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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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