Molecular sudoku
A team of scientists from the Catalan Institute of Nanotechnology, ICREA and UAB investigated the properties of a special kind of sudoku, made by assembling tiny molecules into a 3x3 square array
2011-10-06
(Press-News.org) As reported this week in Nature Communications, the researchers used the atomically-sharp tip of a scanning tunneling microscope to move 1-nanometer sized molecules on top of a silver substrate. The tip is controlled with such great accuracy that it is possible to precisely choose the position of each molecule and build tiny molecular squares, crosses, and chains of controlled size and orientation. The same tip is then used as a mobile electrode to probe the electrical conductivity of the molecules as a function of their position in the array. Figures a-d show an example of such measurements: a represent the topography of a "sudoku" molecular cluster, whereas b-d show regions of high conductivity at different voltages. At low voltage, electrons prefer to pass through the corner molecules, whereas at high voltage, only the central molecule is conducting. This is so because the conductivity depends strongly on a small set of electronic states, which conduct electricity to the substrate, and these are modified by the presence of side-to-side neighbors.
The molecular conductance was found to vary strongly not only from one molecule to another, but also within each molecule, due to the possibility of exploiting different electron transport channels at different positions. Such conduction channels arise from the excitation of internal degrees of freedom of the molecules, such as atomic vibrations and magnetic coupling of the electronic spins. All together, these results demonstrate the intricacy and beauty of molecular electronics, providing a glimpse of its advantages, such as the fabrication of versatile miniaturized circuits, and challenges, which may prove harder to solve than a sudoku game.
INFORMATION:
Spin coupling and relaxation inside molecule-metal contacts
Aitor Mugarza1,2*, Cornelius Krull1,2, Roberto Robles2, Sebastian Stepanow1,2, Gustavo Ceballos1,2, Pietro Gambardella1,2,3,4
1 Catalan Institute of Nanotechnology (ICN), UAB Campus, E-08193 Barcelona, Spain
2 Centre d'Investigacions en Nanociència i Nanotecnologia (CIN2), UAB Campus, E-08193 Barcelona, Spain
3 Institució Catalana de Recerca i Estudis Avançats (ICREA)
4 Departament de Física, Universitat Autonoma de Barcelona, E-08193 Barcelona, Spain
DOI: 10.1038/ncomms1497
On-line versión will be published 4 October de 2011 a las 18:00 horas
For further information:
Catalan Institute of Nanotechnology (ICN) www.icn.cat
Contact: Prof. Dr. Pietro Gambardella, pietro.gambardella@icn.cat
Communication Dept.: Ana de la Osa, ana.delaosa.icn@uab.es
Tel: + (34) 93 581 4963
END
ELSE PRESS RELEASES FROM THIS DATE:
2011-10-06
A tracheostomy performed within the first seven days after a severe head injury results in better overall patient outcome, according to a team of Penn State College of Medicine researchers. This is especially true for patients who have a greater chance of surviving when admitted to the hospital.
A tracheostomy is an opening created in the front of the neck directly into the trachea to allow unimpeded breathing. (A tracheotomy is the act of making that opening.)
"The CDC estimates that more than 200,000 individuals are hospitalized annually for traumatic brain injury," ...
2011-10-06
In a recent ruling by the Massachusetts Court of Appeals, the Commonwealth's Sex Offender Registry Board may not require an individual to register as a Level 2 sex offender based solely on a conviction of possessing child pornography.
Massachusetts has three levels of sex offenders, which are based on a person's individual risk of reoffending and the perceived danger to the public. Level 1 offenders have a low risk of committing future crimes and pose a minimal public safety risk. The list of Level 1 offenders is not available to the general public. However, law enforcement ...
2011-10-06
If an electric car wants to be environmentally friendly it must weigh as little as possible, because when the light turns green every additional pound/kilogram must be accelerated with considerable energy expenditure. And the lighter the electric vehicle, the longer it can be on the road without having to be plugged back into a power outlet. To advance the symbiosis between electromobility and lightweight construction, engineers from the Fraunhofer Institute for Chemical Technology ICT in Pfinztal, Germany, are developing manufacturing concepts that have one goal – they ...
2011-10-06
Trick-or-treating is a great way for kids to have fun, create cherished memories and indulge a youthful sweet tooth. But, when caught up in the spirit of the holiday, many parents forget that bumps, bruises and far more frightening injuries are also an unfortunate possibility when an unusual number of children take to the streets.
Pedestrian Accidents Involving Cars and Children Far More Common on October 31
Studies have shown that the number of pedestrian deaths involving children age 15 and younger is 4.5 times higher on Halloween night compared to all other nights ...
2011-10-06
MIAMA BEACH, FL (October 5, 2011)––Approximately 10-20 percent of prostate cancer patients have a family history of the disease. There are three major factors that are used to evaluate the extent and aggressiveness of prostate cancer, help make treatment decisions, and estimate prognosis: the Prostate Specific Antigen Level (PSA), Gleason score (GS) from the biopsy, and the digital rectal exam findings (DRE). However, men with a family history of prostate cancer have often been feared to have a more aggressive form of the disease not otherwise represented by these three ...
2011-10-06
Advanced imaging with Positron Emission Tomography (PET) scans shows great promise in predicting which patients with inoperable lung cancer have more aggressive tumors and need additional treatment following standard chemotherapy/radiation therapy, according to new research.
Mitch Machtay, MD, of the Seidman Cancer Center at University Hospitals (UH) Case Medical Center and principle investigator for the study, presented the significant data today at 2 pm at the annual meeting of the American Society for Radiation Oncology (ASTRO) in Miami Beach, Fla. The National Cancer ...
2011-10-06
In these hard economic times, many couples are sticking together solely because of perceived monetary impediments to divorce. With the right help, however, you may not have to choose between happiness and financial wellbeing.
Divorce and the Economy
According to a study conducted by the University of Virginia, nearly 40 percent of married couples who were planning on a divorce or separation before the recession put their divorce on hold once the economy crashed. While the choice to abandon the pursuit of a divorce is no doubt complex and there are multiple reasons ...
2011-10-06
In the best of circumstances, raising a toddler is a daunting undertaking. But parents under long-term stress often find it particularly challenging to tap into the patience, responsiveness, and energy required for effective child rearing.
Now research from a University of Rochester team helps to explain why chronic stress and parenting are such a toxic mix. The study finds that ongoing strains, like poverty or depression, disrupt the body's natural stress response, making mothers more likely to engage in a host of problematic parenting behaviors, including neglect, ...
2011-10-06
In 2010, more than 2,000 businesses went through an immigration audit. And this year, ICE has already audited many more companies, including sending out 1,000 notification letters to businesses in early June alone. In a time when employers have enough to worry about, they must also make concerted efforts to ensure their employees are legally qualified to work in the U.S.
Under the Obama administration, the focus on illegal immigration has moved from undocumented immigrants to their potential employers. Gone are the days of loud immigration raids like the ones we saw ...
2011-10-06
COLUMBUS, Ohio – Researchers recently isolated 63 unique dust particles from their laboratory – and that's just the beginning.
The chemists were testing a new kind of sensor when dust got stuck inside it, and they discovered that they could measure the composition of single dust particles.
In a recent issue of The Journal of Physical Chemistry C, they describe how the discovery could aid the study respiratory diseases caused by airborne particles.
Most dust is natural in origin, explained James Coe, professor of chemistry at Ohio State University. The 63 particles ...
LAST 30 PRESS RELEASES:
[Press-News.org] Molecular sudoku
A team of scientists from the Catalan Institute of Nanotechnology, ICREA and UAB investigated the properties of a special kind of sudoku, made by assembling tiny molecules into a 3x3 square array
