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Nov 09

Reported by Mike Ross, in Stanford News Report, 27 September 2013.

The tiny new technology could spawn new generations of smaller, less expensive devices for science and medicine.

The nanostructured glass chip is smaller than a grain of rice (by Brad Plummer).

In an advance that could dramatically shrink particle accelerators for science and medicine, researchers used a laser to accelerate electrons at a rate 10 times higher than conventional technology in a nanostructured glass chip smaller than a grain of rice.

The achievement was reported today in the journal Nature by a team including scientists from the U.S. Department of Energy’s SLAC National Accelerator Laboratory and Stanford University.

“We still have a number of challenges before this technology becomes practical for real-world use, but eventually it would substantially reduce the size and cost of future high-energy particle colliders for exploring the world of fundamental particles and forces,” said Joel England, the SLAC physicist who led the experiments. Continue reading »

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Oct 21

Uploaded by Stanford University Channel on YouTube, Stanford Electrical Engineering Department, Stanford EE380 Computer Systems Colloquium.

(November 9, 2011) R. Stanley Williams presents the results of his work with prototype memristors at HP, including their fundamental properties, potential uses in circuits, and speed and energy measurements.

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Sep 26

Reported by Tom Abate, in Stanford News, 26 September 2013.

Unprecedented feat points toward a new generation of energy-efficient electronics!

This wafer contains tiny computers using carbon nanotubes, a material that could lead to smaller, more energy-efficient processors (by Norbert von der Groeben).

A team of Stanford engineers has built a basic computer using carbon nanotubes, a semiconductor material that has the potential to launch a new generation of electronic devices that run faster, while using less energy, than those made from silicon chips.

This unprecedented feat culminates years of efforts by scientists around the world to harness this promising but quirky material.

The achievement is reported today in an article on the cover of the  journal Nature written by Max Shulaker and other doctoral students in electrical engineering. The research was led by Stanford professors Subhasish Mitra and H.-S. Philip Wong. Continue reading »

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Sep 25

Reported by Wiebe van der Veen, University of Twente, 20 September 2013.

Extreme engineering on the smallest scales.

A copper-phthalocyanine molecule bridges the 1.6 nanometre-wide gap between two gold nanowires. The copper atom of this molecule floats in the vacuum above this 'gap' between the wires

He isn’t just occupied crafting ultra-thin gold and iridium wires: Tijs Mocking, researcher at the University of Twente’s MESA+ Institute for Nanotechnology, manages to bridge the ‘gap’ between two gold nanowires, each just a few atoms high, with a single molecule. This bridge can serve to detect new physical effects or may act as a switch. Tijs Mocking obtained his PhD degree on 19 September.

Place a layer of gold only a few atoms high on a surface bed of germanium, apply heat to it, and wires will form of themselves. Gold-induced wires is what Mocking prefers to call them. Not ‘gold wires’, as the wires are not made solely out of gold atoms but also contain germanium. They are no more than a few atoms in height and are separated by no more than 1.6 nanometres (a nanometre is one millionth of a millimetre). Nanotechnologists bridge this small ‘gap’ with a copper-phthalocyanine molecule. A perfect fit. Continue reading »

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Sep 05

Reported by Aviva Hope Rutkin, in Brookhaven National Laboratory News, 02 Sep. 2012.

Atomic scale visualization of the single molecule junctions formed with two equivalent pathways (left) and one pathway (right), including the bonding to the tips of two gold electrodes and a schematic of the external electrical circuit.

In a paper published in Nature Nanontechnology on September 2, 2012, scientists from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University’s departments of Chemistry and of Applied Physics explore the laws that govern electronic conductance in molecular scale circuits.

“Everyone who has worked with basic electronic circuits knows that there are some simple rules of the road, like Ohm’s Law,” explains collaborator Mark Hybertsen, a physicist at Brookhaven’s Center for Functional Nanomaterials (CFN). Hybertsen provided the theory to model the observed circuit behavior with the CFN’s computational tools. “For several years we have been asking fundamental questions to probe how those rules might be different if the electronic circuit is shrunk down to the scale of a single molecule.” Continue reading »

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Sep 04

Reported by University of Bristol, Press Releases, 03 Sep. 2012.

Example of a silicon quantum chip next to a 20 pence coin.

An international research collaboration led by scientists from the University of Bristol, UK, has developed a new approach to quantum computing that could lead to the mass-manufacture of new quantum technologies.

Scientists from the University of Bristol’s Centre for Quantum Photonics have developed a silicon chip that will pave the way to the mass-manufacture of miniature quantum chips. The announcement was made at the launch of the 2012 British Science Festival [4 to 9 September].

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Mar 23

By Y. Tanizawa, Y. Okamoto, K. Tsuzuki, Y. Nagao, N. Yoshida, R. Tero, S. Iwasa, A. Hiraishi, Y. Suda, H. Takikawa, R. Numano, H. Okada, R. Ishikawa and A. Sandhu, in J. Phys.: Conf. Ser. 352 012011 doi:10.1088/1742-6596/352/1/012011

Abstract: The wide-ranging industrial application of graphene and related compounds has led researchers to devise methods for the synthesis of high quality graphene. We recently reported on the chemical synthesis, patterning, and doping of graphene films by the chemical exfoliation of graphite into graphene oxide (GO) with subsequent chemical reduction into graphene films [1, 2]. Here, we describe a hybrid approach for the synthesis of reduced graphene sheets, where chemically derived GO was reduced by microorganisms extracted from a riverside near the University. Our procedure enabled the production of ~100 μm sized reduced graphene sheets, which showed excellent Raman spectra associated with high quality reduced graphene. We give a detailed account of the relationship between the type of microorganisms and the properties of the resulting reduced graphene.

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Mar 16

Reported by Jennifer Marcus, in UCLA Newsroom, 15 March 2012.

Electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, differ from regular capacitors that you would find in your TV or computer in that they store sustantially higher amounts of charges. They have garnered attention as energy storage devices as they charge and discharge faster than batteries, yet they are still limited by low energy densities, only a fraction of the energy density of batteries. An EC that combines the power performance of capacitors with the high energy density of batteries would represent a significant advance in energy storage technology. This requires new electrodes that not only maintain high conductivity but also provide higher and more accessible surface area than conventional ECs that use activated carbon electrodes. Continue reading »
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Mar 10

Reported by Bob Yirka, in PhysOrg weblog, 5 March 2012.

The past several years have seen a virtual explosion in the amount of research dedicated to graphene and as a result there has been a nearly constant stream of news pertaining to new discoveries regarding its attributes. Now it appears, graphene is about to be upstaged by a more interesting cousin called graphyne. Graphene, as most everyone is aware by now, is a single layer of carbon atoms arranged in a hexagonal or chicken-wire pattern. Graphyne is also a single layer of carbon atoms, but it comes in several different types of patterns, which likely make it more versatile. Now new computer simulations regarding its properties have been done by a team of researchers in Germany, who report in Physical Review Letters, that their research shows that some types of graphyne structures allow for electron flow in just one direction.

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Feb 23

By Martin Fuechsle, Jill A. Miwa, Suddhasatta Mahapatra, Hoon Ryu, Sunhee Lee, Oliver Warschkow, Lloyd C. L. Hollenberg, Gerhard Klimeck & Michelle Y. Simmons in Nature Nanotechnology (2012), Published online, 19 February 2012.

Abstract: The ability to control matter at the atomic scale and build devices with atomic precision is central to nanotechnology. The scanning tunnelling microscope1 can manipulate individual atoms2 and molecules on surfaces, but the manipulation of silicon to make atomic-scale logic circuits has been hampered by the covalent nature of its bonds. Resist-based strategies have allowed the formation of atomic-scale structures on silicon surfaces3, but the fabrication of working devices—such as transistors with extremely short gate lengths4, spin-based quantum computers5, 6, 7, 8 and solitary dopant optoelectronic devices9—requires the ability to position individual atoms in a silicon crystal with atomic precision. Here, we use a combination of scanning tunnelling microscopy and hydrogen-resist lithography to demonstrate a single-atom transistor in which an individual phosphorus dopant atom has been deterministically placed within an epitaxial silicon device architecture with a spatial accuracy of one lattice site. The transistor operates at liquid helium temperatures, and millikelvin electron transport measurements confirm the presence of discrete quantum levels in the energy spectrum of the phosphorus atom. We find a charging energy that is close to the bulk value, previously only observed by optical spectroscopy.

Read more in doi:10.1038/nnano.2012.21.

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