Tuesday, 8 March 2011

Silicon Oxide: A Non-innocent Surface for Molecular Electronics and Nanoelectronics Studies

Jun Yao, Lin Zhong*§, Douglas Natelson*§, and James M. Tour*

J. Am. Chem. Soc.2011133 (4), pp 941–948
DOI: 10.1021/ja108277r
Publication Date (Web): December 22, 2010

Silicon oxide (SiOx) has been widely used in many electronic systems as a supportive and insulating medium. Here, we demonstrate various electrical phenomena such as resistive switching and related nonlinear conduction, current hysteresis, and negative differential resistance intrinsic to a thin layer of SiOx. These behaviors can largely mimic numerous electrical phenomena observed in molecules and other nanomaterials, suggesting that substantial caution should be paid when studying conduction in electronic systems with SiOxas a component. The actual electrical phenomena can be the result of conduction from SiOxat a post soft-breakdown state and not the presumed molecular or nanomaterial component. These electrical properties and the underlying mechanisms are discussed in detail.


Wednesday, 2 March 2011

02 March - High-Resolution Transmission Electron Microscopy Study of Electrically-Driven Reversible Phase Change in Ge2Sb2Te5 Nanowires

Today Jorge will present the following paper:


High-Resolution Transmission Electron Microscopy Study of Electrically-Driven Reversible Phase Change in Ge2Sb2Te5 Nanowires

Yeonwoong Jung, Sung-Wook Nam, and Ritesh Agarwal
Nano Lett., Article ASAP
DOI: 10.1021/nl104537c

By combining high-resolution transmission electron microscopy (HRTEM) characterization and electrical measurements on a unique device platform, we study the reversible electrically-driven phase-change characteristics of self-assembled Ge2Sb2Te5 nanowires. Detailed HRTEM analyses are used to correlate and understand the effect of full and intermediate structural transformations on the measured electrical properties of the nanowire devices. The study demonstrates that our unique approach has the potential to provide new information regarding the dynamic structural and electrical states of phase-change materials at the nanoscale, which will aid the design of future phase-change memory devices.

Monday, 28 February 2011

Fully Electrical Read-Write Device Out of a Ferromagnetic Semiconductor

Phys. Rev. Lett. 106, 057204 (2011) [4 pages]


S. Mark, P. Dürrenfeld, K. Pappert, L. Ebel, K. Brunner, C. Gould, and L. W. Molenkamp

URL: http://link.aps.org/doi/10.1103/PhysRevLett.106.057204
DOI: 10.1103/PhysRevLett.106.057204
 
We report the realization of a read-write device out of the ferromagnetic semiconductor (Ga,Mn)As as the first step to a fundamentally new information processing paradigm. Writing the magnetic state is achieved by current-induced switching and readout of the state is done by the means of the tunneling anisotropic magnetoresistance effect. This 1 bit demonstrator device can be used to design an electrically programmable memory and logic device.

Monday, 7 February 2011

The birth of topological insulators

Joel E. Moore1,2
Nature 464, 194-198 (11 March 2010) | doi:10.1038/nature08916;


Certain insulators have exotic metallic states on their surfaces. These states are formed by topological effects that also render the electrons travelling on such surfaces insensitive to scattering by impurities. Such topological insulators may provide new routes to generating novel phases and particles, possibly finding uses in technological applications in spintronics and quantum computing.




http://www.nature.com/nature/journal/v464/n7286/full/nature08916.html

Saturday, 5 February 2011

What is Watson?

Using advanced computing and emerging technology, IBM is building a natural language processing computer code-named Watson to compete in the game show Jeopardy.



Friday, 4 February 2011

High-Resolution Transmission Electron Microscopy Study of Electrically-Driven Reversible Phase Change in Ge2Sb2Te5 Nanowires

Yeonwoong Jung, Sung-Wook Nam, and Ritesh Agarwal*


Nano Lett., Article ASAP
DOI: 10.1021/nl104537c

By combining high-resolution transmission electron microscopy (HRTEM) characterization and electrical measurements on a unique device platform, we study the reversible electrically-driven phase-change characteristics of self-assembled Ge2Sb2Te5 nanowires. Detailed HRTEM analyses are used to correlate and understand the effect of full and intermediate structural transformations on the measured electrical properties of the nanowire devices. The study demonstrates that our unique approach has the potential to provide new information regarding the dynamic structural and electrical states of phase-change materials at the nanoscale, which will aid the design of future phase-change memory devices.



Wednesday, 2 February 2011

02 February - Nanopipettes for Metal Transport

Peiman will present the following paper:

Nanopipettes for Metal Transport

      K. Svensson1, H. Olin2, and E. Olsson1 

Phys. Rev. Lett. 93, 145901 (2004) [4 pages]

Here we demonstrate, for the first time experimentally, a nanopipette action for metals using multiwalled carbon nanotubes. The process relies on electromigration forces, created at high electron current densities, enabling the transport of material inside the hollow core of carbon nanotubes. In this way nanoparticles of iron were transported to and from electrically conducting substrates.