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Primeur weekly 2011-09-05

Exascale supercomputing

Intel forms new subsidiary focused on HPC: Intel Federal LLC ...

The Cloud

VMware and Cisco collaborate on Cloud innovation ...

Dell launches its first public Cloud offering; Dell Cloud with VMware vCloud Datacenter Service ...

Harris Corporation and VMware to deliver trusted enterprise Cloud to federal and commercial customers ...

NetApp and VMware help transform IT and make Cloud a reality ...

Symantec and VMware announce strategic partnership to deliver Desktop-as-a-Service solutions ...

New VMware vCloud offerings accelerate journey to the enterprise hybrid Cloud ...

VMware introduces new platform for enterprise Database as a Service ...

HP speeds and simplifies virtual infrastructure deployments ...

Cisco to provide Hosted Collaboration Solution for NTT Communications Cloud-based Unified Communications Service ...

EuroFlash

PRACE to organize Autumn School 2011, 25-27 October 2011 in Bruyères-le-Châtel, France ...

Kolkata institute inks accord with CERN ...

The quantum tunneling effect leads electron transport in porphyrins ...

Graphene's shining light could lead to super-fast Internet ...

USFlash

IBM expands power licensing as leading developers eye new applications ...

IBM and Jeopardy! relive history with encore presentation of Jeopardy!: The IBM challenge ...

VBI and Convey Computer partner to deliver technology to biomedical, life sciences researchers ...

Astrophysicists report first simulation to create a Milky Way-like galaxy ...

NIST achieves record-low error rate for quantum information processing with one qubit ...

Director appointed for New Zealand eScience Infrastructre ...

Berkeley scientists discover an 'instant cosmic classic' supernova ...

IEEE Xplore digital library reaches three million documents as pace of technical contributions accelerates ...

Oracle achieves world record result on SAP Assemble-to-Order (ATO) Standard Application Benchmark ...

UCSB physicists demonstrate the quantum von Neumann architecture ...

The quantum tunneling effect leads electron transport in porphyrins

1 Sep 2011 Oviedo - A research centre of the CSIC participates in a study that refutes the hypothesis that their movement is based on jumps from one region to another. The porphyrins may be used in quantum computing since they keep the wave nature of electrons.

Porphyrins are organic molecules that appear in the central region of macromolecules such as chlorophyll and hemoglobin, and have a metal atom at their centre 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", explained the responsible of the work at the Nanomaterials and Nanotechnology Research Center - a joint research centre of the CSIC, the University of Oviedo and the Government of the Principality of Asturias - Víctor Manuel García.

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", explained Víctor Manuel García. 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", stated the researcher.

"The progressive miniaturization of integrated circuits make the electronic elements increasingly approach the atomic limit", stated Víctor Manuel 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", concluded Víctor Manuel Garcia.

The study counted on the participation of researchers from the UK universities of Liverpool, Lancaster, Oxford and Cardiff, and the universities of Zaragoza and Oviedo, belonging the researcher to the latter one.

Source: CSIC - Consejo Superior de Investigaciones Científicas

Back to Table of contents

Primeur weekly 2011-09-05

Exascale supercomputing

Intel forms new subsidiary focused on HPC: Intel Federal LLC ...

The Cloud

VMware and Cisco collaborate on Cloud innovation ...

Dell launches its first public Cloud offering; Dell Cloud with VMware vCloud Datacenter Service ...

Harris Corporation and VMware to deliver trusted enterprise Cloud to federal and commercial customers ...

NetApp and VMware help transform IT and make Cloud a reality ...

Symantec and VMware announce strategic partnership to deliver Desktop-as-a-Service solutions ...

New VMware vCloud offerings accelerate journey to the enterprise hybrid Cloud ...

VMware introduces new platform for enterprise Database as a Service ...

HP speeds and simplifies virtual infrastructure deployments ...

Cisco to provide Hosted Collaboration Solution for NTT Communications Cloud-based Unified Communications Service ...

EuroFlash

PRACE to organize Autumn School 2011, 25-27 October 2011 in Bruyères-le-Châtel, France ...

Kolkata institute inks accord with CERN ...

The quantum tunneling effect leads electron transport in porphyrins ...

Graphene's shining light could lead to super-fast Internet ...

USFlash

IBM expands power licensing as leading developers eye new applications ...

IBM and Jeopardy! relive history with encore presentation of Jeopardy!: The IBM challenge ...

VBI and Convey Computer partner to deliver technology to biomedical, life sciences researchers ...

Astrophysicists report first simulation to create a Milky Way-like galaxy ...

NIST achieves record-low error rate for quantum information processing with one qubit ...

Director appointed for New Zealand eScience Infrastructre ...

Berkeley scientists discover an 'instant cosmic classic' supernova ...

IEEE Xplore digital library reaches three million documents as pace of technical contributions accelerates ...

Oracle achieves world record result on SAP Assemble-to-Order (ATO) Standard Application Benchmark ...

UCSB physicists demonstrate the quantum von Neumann architecture ...