Navigation Links
The quantum tunneling effect leads electron transport in porphyrins
Date:9/1/2011

Porphyrins are organic molecules that appear in the central region of macromolecules such as chlorophyll and hemoglobin, and have a metal atom at their center that determines their specific function. The importance of these molecules in the field of molecular electronics lies in their "ease of transfer electrons from one region to another" explains the responsible of the work at the Nanomaterials and Nanotechnology Research Center (a joint research center of the CSIC, the University of Oviedo and the Government of the Principality of Asturias) Vctor Manuel Garca.

To determine the electronic transport mechanism in porphyrins, the team has evaluated the change in their electrical conductivity as a function of distance and temperature, in chains of one, two and three units of porphyrin anchored at their ends to gold surfaces, which act as electrodes.

According to the laws governing hopping transport, the conductivity of the porphyrins increases with temperature but decreases slowly with distance. Under this mechanism, electrons pass from one electrode to another by jumping from one region of the molecule to another, thus being their movement more similar to that of a particle than to a wave. The temperature increases their ability to jump and, therefore, the conductance, while the length decreases it.

On the contrary, the tunneling effect is based on the fact that electrons have a certain probability of disappearing from one electrode and reappearing in the other. This probability depends on the type of molecule between the electrodes.

Under this mechanism, the temperature can also increase the electrical conductance, "since it increases the amount of available electrons to be transported", explains Garca. However, the length effect changes the conductance exponentially. A increase of the length of the molecular wire drastically decreases the probability of electrons to appear at the other side.

The weak dependence of the porphyrins' conductivity as a function of distance as well as the temperature dependence "led to believe that the main transport mechanism was hopping. However, experiments and theoretical calculations carried out by the research team have shown that electron transport in these systems is actually led by the tunneling effect", says the researcher.

Computer Components

"The progressive miniaturization of integrated circuits make the electronic elements increasingly approach the atomic limit", says Garcia. Therefore, the research aims to find molecules that can perform the functions of electronic components since they can be produced in a simple and cost-effective way. The electron transport mechanism shown in this study may promote the use of porphyrins in devices for quantum computers. These computers are based on quantum mechanics, so the transport of electrons by tunneling may be appropriate for them. When electrons disappear and reappear at one electrode or another "they retain their wave nature, and therefore also their quantum properties", concludes Garcia.


'/>"/>

Contact: Marta del Amo
m.delamo@orgc.csic.es
0034-915-681-471
CSIC, Consejo Superior de Investigaciones Cientficas
Source:Eurekalert  

Related biology technology :

1. UCSB physicists demonstrate the quantum von Neumann architecture
2. Manufacturing method paves way for commercially viable quantum dot-based LEDs
3. Quantum Learning Signs Licensing Agreement with Jay Elliot, Author of "The Steve Jobs Way"
4. Armchair science: DNA strands that select nanotubes are first step to a practical quantum wire
5. Graphenes quantum leap takes electronics a step closer
6. Discovery may overcome obstacle for quantum computing
7. Cadmium selenide quantum dots degrade in soil, releasing their toxic guts, study finds
8. U.Va.s Pfister accomplishes breakthrough toward quantum computing
9. NIST mechanical micro-drum cooled to quantum ground state
10. UCL grows first telecommunications wavelength quantum dot laser on a silicon substrate
11. Innovative device for quantum simulations
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
The quantum tunneling effect leads electron transport in porphyrins
(Date:6/23/2016)... Mass. , June 23, 2016   ... development of novel compounds designed to target cancer ... napabucasin, has been granted Orphan Drug Designation from ... the treatment of gastric cancer, including gastroesophageal junction ... stemness inhibitor designed to inhibit cancer stemness pathways ...
(Date:6/23/2016)... , June 23, 2016 Houston ... with the Cy-Fair Sports Association to serve as ... the agreement, Houston Methodist Willowbrook will provide sponsorship ... and connectivity with association coaches, volunteers, athletes and ... with the Cy-Fair Sports Association and to bring ...
(Date:6/23/2016)... -- The Biodesign Challenge (BDC), a university competition that asks ... systems and biotechnology, announced its winning teams at the ... York City . The teams, chosen ... MoMA,s Celeste Bartos Theater during the daylong summit. Keynote ... of architecture and design, and Suzanne Lee , ...
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the sample tracking software company, ... Crime Laboratory, has joined STACS DNA as a Field Application Specialist. , “I ... President and COO of STACS DNA. “In further expanding our capacity as a scientific ...
Breaking Biology Technology:
(Date:5/16/2016)... 2016   EyeLock LLC , a market leader ... of an IoT Center of Excellence in ... development of embedded iris biometric applications. EyeLock,s ... and security with unmatched biometric accuracy, making it the ... DNA. EyeLock,s platform uses video technology to deliver a ...
(Date:4/28/2016)... April 28, 2016 First quarter 2016:   ... 966% compared with the first quarter of 2015 The ... 589.1 M (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) ... guidance is unchanged, SEK 7,000-8,500 M. The operating margin ...
(Date:4/15/2016)... April 15, 2016 Research ... Gait Biometrics Market 2016-2020,"  report to their offering.  ... ) , ,The global gait biometrics market is ... during the period 2016-2020. Gait analysis ... can be used to compute factors that are ...
Breaking Biology News(10 mins):