Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > The smallest conceivable switch Targeted proton transfer within a molecule

Physicists at the Technische Universitaet Muenchen have created a nano switch based on a single porphyrin ring. If one of two protons from the inside of the ring is removed, the remaining proton can take on any one of four positions, initiated by a single tunnel electron from the tip of a scanning tunneling microscope.

Credit: Knud Seufert / Technische Universitaet Muenchen
Physicists at the Technische Universitaet Muenchen have created a nano switch based on a single porphyrin ring. If one of two protons from the inside of the ring is removed, the remaining proton can take on any one of four positions, initiated by a single tunnel electron from the tip of a scanning tunneling microscope.

Credit: Knud Seufert / Technische Universitaet Muenchen

Abstract:
For a long time miniaturization has been the magic word in electronics. Dr. Willi Auwaerter and Professor Johannes Barth, together with their team of physicists at the Technische Universitaet Muenchen (TUM), have now presented a novel molecular switch in the journal Nature Nanotechnology. Decisive for the functionality of the switch is the position of a single proton in a porphyrin ring with an inside diameter of less than half a nanometer. The physicists can set four distinct states on demand.

The smallest conceivable switch Targeted proton transfer within a molecule

Munich, Germany | Posted on December 12th, 2011

Porphyins are ring-shaped molecules that can flexibly change their structure, making them useful for a wide array of applications. Tetraphenylporphyrin is no exception: It likes to take on a saddle shape and is not limited in its functionality when it is anchored to a metal surface. The molecule holds has a pair of hydrogen atoms that can change their positions between two configurations each. At room temperature this process takes place continuously at an extremely rapid rate.

In their experiment, the scientists suppressed this spontaneous movement by cooling the sample. This allowed them to induce and observe the entire process in a single molecule using a scanning tunneling microscope. This kind of microscope is particularly well suited for the task since - in contrast to other methods - it can be used not only to determine the initial and final states, but also allows the physicists to control the hydrogen atoms directly. In a further step they removed one of the two protons from the inside of the porphyrin ring. The remaining proton could now take on any one of four positions. A tiny current that flows through the fine tip of the microscope stimulates the proton transfer, setting a specific configuration in the process.

Although the respective positions of the hydrogen atoms influence neither the basic structure of the molecule nor its bond to the metallic surface, the states are not identical. This small but significant difference, taken together with the fact that the process can be arbitrarily repeated, forms the basis of a switch whose state can be changed up to 500 times per second. A single tunneled electron initiates the proton transfer.

The molecular switch has a surface area of only one square nanometer, making it the smallest switch implemented to date. The physicists are thrilled by their demonstration and are also very happy about new insights into the mechanism behind the proton transfer resulting from their study. Knud Seufert played a key role with his experiments: "To operate a four-state switch by moving a single proton within a molecule is really fascinating and represents a true step forward in nano-scale technologies."

This research was funded by the European Research Council (ERC Advanced Grant MolArt, No. 247299), the Excellence Cluster Munich-Centre for Advanced Photonics (MAP) and the Institute for Advanced Study of the TU Muenchen.

####

For more information, please click here

Contacts:
Dr. Andreas Battenberg

49-892-891-0510

Copyright © Technische Universitaet Muenchen

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Original publication: Willi Auwaerter, Knud Seufert, Felix Bischoff, David Ecija, Saranyan Vijayaraghavan, Sushobhan Joshi, Florian Klappenberger, Niveditha Samudrala, and Johannes V. Barth

Related News Press

News and information

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

An accelerated pipeline to open materials research: ORNL workflow system unites imaging, algorithms, and HPC to advance materials discovery and design July 24th, 2016

Russian physicists discover a new approach for building quantum computers: Physicists find a way of 'bundling together' multiple elements of a quantum computer July 24th, 2016

A 'smart dress' for oil-degrading bacteria July 24th, 2016

Govt.-Legislation/Regulation/Funding/Policy

An accelerated pipeline to open materials research: ORNL workflow system unites imaging, algorithms, and HPC to advance materials discovery and design July 24th, 2016

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

Weird quantum effects stretch across hundreds of miles July 21st, 2016

Scientists glimpse inner workings of atomically thin transistors July 21st, 2016

Molecular Machines

New remote-controlled microrobots for medical operations July 23rd, 2016

Pushing a single-molecule switch: An international team of researchers from Donostia International Physics Center, Fritz-Haber Institute of the Max Planck Society, University of Liverpool, and the Polish Academy of Sciences has shown a new way to operate a single-molecule switch July 19th, 2016

Researchers harness DNA as the engine of super-efficient nanomachine: New platform detects traces of everything from bacteria to viruses, cocaine and metals July 10th, 2016

On the path toward molecular robots: Scientists at Japan's Hokkaido University have developed light-powered molecular motors that repetitively bend and unbend, bringing us closer to molecular robots. July 8th, 2016

Molecular Nanotechnology

New remote-controlled microrobots for medical operations July 23rd, 2016

Scientists develop way to upsize nanostructures into light, flexible 3-D printed materials: Virginia Tech, Livermore National Lab researchers develop hierarchical 3-D printed metallic materials July 20th, 2016

Pushing a single-molecule switch: An international team of researchers from Donostia International Physics Center, Fritz-Haber Institute of the Max Planck Society, University of Liverpool, and the Polish Academy of Sciences has shown a new way to operate a single-molecule switch July 19th, 2016

Researchers harness DNA as the engine of super-efficient nanomachine: New platform detects traces of everything from bacteria to viruses, cocaine and metals July 10th, 2016

Nanoelectronics

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

Scientists glimpse inner workings of atomically thin transistors July 21st, 2016

'Green' electronic materials produced with synthetic biology July 16th, 2016

Discoveries

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

An accelerated pipeline to open materials research: ORNL workflow system unites imaging, algorithms, and HPC to advance materials discovery and design July 24th, 2016

Russian physicists discover a new approach for building quantum computers: Physicists find a way of 'bundling together' multiple elements of a quantum computer July 24th, 2016

A 'smart dress' for oil-degrading bacteria July 24th, 2016

Announcements

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

An accelerated pipeline to open materials research: ORNL workflow system unites imaging, algorithms, and HPC to advance materials discovery and design July 24th, 2016

Russian physicists discover a new approach for building quantum computers: Physicists find a way of 'bundling together' multiple elements of a quantum computer July 24th, 2016

A 'smart dress' for oil-degrading bacteria July 24th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic