Physicists manipulate temperature of Kondo effect

January 31, 2007

Physicists at Ohio University have learned how to manipulate the temperature of the Kondo effect, which they observed for the first time in a two-dimensional molecular layer.

In a recent issue of the journal Physical Review Letters, the scientists reported that they were able to manipulate and tune the Kondo effect by removing one molecule at a time from a small molecular assembly.

The researchers created a hexagonal unit of molecules by manipulating the nearest neighbor molecules. Credit: Saw-Wai Hla

The most important and useful property of molecules in nanotechnology is their ability to self-assemble and form molecular layers, said lead author Saw-Wai Hla, an associate professor of physics and astronomy at Ohio University. Many molecules, each having specific properties useful for nanodevices, can spontaneously assemble on substrates.

“This process is critical for the ‘bottom up’ approach in nanotechnology,” Hla said. “The manipulation of the Kondo effect inside the molecular layer is significant and may have an impact on the development of nanoscale molecular memory devices and for quantum computation.”

In the recent experiment, porphyrin molecules with a magnetic cobalt atom caged at each molecule’s center were self-assembled on a copper crystal surface. The researchers used a custom built low-temperature scanning tunneling microscope to create a hexagonal unit of molecules by manipulating the nearest neighbor molecules.

The scanning tunneling microscope tip was used to detect the Kondo effect above the center molecule at — 450 F. The scientists found that reducing the number of molecules surrounding the hexagonal unit increased the Kondo temperature. When the center molecule is surrounded by six molecules, it has little chance to interact with outside electrons.

When the neighboring molecules are removed one at a time, however, the center unit can interact with surrounding free electrons from the copper surface. This changes the Kondo temperature, which is an indicator of how strong the magnetic atom inside the molecule is interacting with the free electrons.

“We are currently storing data at the level of millions, but if molecular memory devices could be developed using this phenomenon, then we could be storing data at the level of billions in the future,” Hla said.

Source: Ohio University

Explore further: Study reveals the mechanisms of a protein that helps moss and green algae defend against too much light

Related Stories

Kondo effect in single magnetic molecules

June 7, 2006

The Kondo effect was first explained more than 40 years ago by a Japanese physicist. It opened a new chapter in the study of fundamental physics. Now, that door is being pushed open a little further, thanks to the efforts ...

Magnetic order in a two-dimensional molecular chessboard

May 22, 2017

Achieving magnetic order in low-dimensional systems consisting of only one or two dimensions has been a research goal for some time. In a new study published in the journal Nature Communications, Uppsala researchers show ...

Targeted virus compels cancer cells to eat themselves

May 2, 2006

An engineered virus tracks down and infects the most common and deadly form of brain cancer and then kills tumor cells by forcing them to devour themselves, researchers at The University of Texas M. D. Anderson Cancer Center ...

Recommended for you

New technique accurately digitizes transparent objects

September 21, 2017

A new imaging technique makes it possible to precisely digitize clear objects and their surroundings, an achievement that has eluded current state-of-the-art 3D rendering methods. The ability to create detailed, 3D digital ...

Gravitational waves may oscillate, just like neutrinos

September 21, 2017

(Phys.org)—Using data from the first-ever gravitational waves detected last year, along with a theoretical analysis, physicists have shown that gravitational waves may oscillate between two different forms called "g" and ...

Detecting cosmic rays from a galaxy far, far away

September 21, 2017

In an article published today in the journal Science, the Pierre Auger Collaboration has definitively answered the question of whether cosmic particles from outside the Milky Way Galaxy. The article, titled "Observation of ...

Physicists publish new findings on electron emission

September 21, 2017

Even more than 100 years after Einstein's explanation of photoemission the process of electron emission from a solid material upon illumination with light still poses challenging surprises. In the report now published in ...

Rapid imaging of granular matter

September 21, 2017

Granular systems such as gravel or powders can be found everywhere, but studying them is not easy. Researchers at ETH Zurich have now developed a method by which pictures of the inside of granular systems can be taken ten ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.