Navigation Links
Stretching molecules yields new understanding of electricity
Date:6/10/2010

Cornell University researchers recently stretched individual molecules and watched electrons flow through them, proving that single-molecule devices can be used as powerful new tools for nanoscale science experiments.

The finding, reported in the June 11 issue of the journal Science, probes the effects of strong electron interactions that can be important when shrinking electronics to their ultimate small size limit--single-molecule devices. The work resulted in the first precision tests of a phenomenon known as the underscreened Kondo effect.

"The main advance in our work is that we show single-molecule devices can be very useful as scientific tools to study an interesting phenomenon that has never before been experimentally accessible," said Dan Ralph, the Cornell physics professor who led the study.

The research was funded in part by the Cornell Center for Materials Research, which is supported by the National Science Foundation's (NSF) Division of Materials Research. NSF's Division of Chemistry also contributed to the project.

"Single-molecule devices can indeed be used as model systems for making detailed quantitative studies of fundamental physics inaccessible by any other technique," said first author Joshua Parks, a postdoctoral associate in Cornell's Department of Chemistry and Chemical Biology.

Using a cobalt-based complex cooled to extremely low temperatures, Ralph, Parks and an international team of researchers watched electrons move through single molecules and accomplished a feat that until now escaped chemists and physicists. They were able to study the resistance of the flow of electricity within a system's electric field as the temperature approaches absolute zero.

This is known as the Kondo effect.

In physics, the Kondo effect is perhaps the most important model for understanding how electrons interact within a system such as a molecule. Because of the Kondo effect, when a spinning molecule is attached to electrodes, interactions between the molecule and electrons lead to coordinated motion of the electrons, resulting in a localized cloud of electrons that cancels out the molecule's spin and permits the electrons to flow with decreasing resistance as the temperature approaches zero degrees Kelvin, -273 degrees Fahrenheit.

However, theories since 1980 have also predicted for certain types of high-spin molecules the possibility of an underscreened Kondo effect, in which the spin of the molecule is not completely cancelled and the resulting correlations between the flowing electrons are not as complete.

The researchers tested the Kondo effect by placing the cobalt-based complex between two electrodes and slowly stretching individual spin-containing molecules. They were able to manipulate the molecule's magnetic properties and make precise tests of how electrical resistance changes with variations in temperature. The results were found to be in good agreement with predictions for the underscreened Kondo effect.

"The research shows mechanical control can be a realistic strategy for manipulating molecular spin states, to supplement or replace the use of magnetic fields in proposed applications such as quantum computing or information storage," said Parks.


'/>"/>

Contact: Bobbie Mixon
bmixon@nsf.gov
703-292-8485
National Science Foundation
Source:Eurekalert

Related biology news :

1. Scripps Research scientists break barrier to creating potential therapeutic molecules
2. New method for producing libraries of important carbohydrate molecules
3. Intracellular express -- why transport protein molecules have brakes
4. Light activated warhead turns modest molecules into super protein killers
5. New sensor array detects single molecules for the first time
6. New cancer-fighting strategy focuses on signaling molecules
7. When molecules leave tire tracks
8. Research at Marshall University may lead to new ways to transport and manipulate molecules
9. Small molecules found to protect cells in multiple models of Parkinsons disease
10. Just like old times: Generating RNA molecules in water
11. New synthetic molecules trigger immune response to HIV and prostate cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/2/2016)... Feb. 2, 2016  Based on its recent ... Sullivan recognizes US-based Intelligent Retinal Imaging Systems (IRIS) ... Award for New Product Innovation. IRIS, a prominent ... North America , is poised to set ... diabetic retinopathy market. The IRIS technology presents superior ...
(Date:1/28/2016)... JOSE, Calif., Jan. 28, 2016 Synaptics (NASDAQ: SYNA ... results for its second quarter ended December 31, 2015. ... second quarter of fiscal 2016 increased 2 percent compared to the ... second quarter of fiscal 2016 was $35.0 million, or $0.93 per ... Non-GAAP net income for the first quarter of fiscal 2016 grew ...
(Date:1/22/2016)... 22, 2016 ... of the  "Global Behavioral Biometric Market ... --> http://www.researchandmarkets.com/research/4lmf2s/global_behavioral ) has announced ... Biometric Market 2016-2020"  report to their ... Markets ( http://www.researchandmarkets.com/research/4lmf2s/global_behavioral ) has announced the ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... , Germany and ... QGEN ; Frankfurt Prime Standard: QIA) today ... Targeted RNA Panels for gene expression profiling, expanding QIAGEN,s ... (NGS). The panels enable researchers to select from over ... changes and discover interactions between genes, cellular phenotypes and ...
(Date:2/11/2016)... 11, 2016  Dovetail Genomics™ LLC today announced that ... for a planned metagenomic genome assembly service. Richard ... genome assembly method in a talk on Friday, February ... Technology conference in Orlando, Fla. ... datasets is difficult. Using its proprietary Chicago ...
(Date:2/11/2016)... (PRWEB) , ... February 11, 2016 , ... ... of its new stem cell treatment clinic in Quito, Ecuador. The new facility ... and trauma applications to patients from around the world. , The new ...
(Date:2/10/2016)... , Feb.10, 2016 ASAE is introducing ... Association Management Companies (AMC) the option of joining or ... annual fee determined by staff size, every employee in ... join ASAE and reap all available member benefits.   ... "Our new organizational membership options will allow organizations of ...
Breaking Biology Technology: