Wednesday, 31 October 2012

Graphene mini-lab

Graphene mini-lab [ Back to EurekAlert! ] Public release date: 31-Oct-2012
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Contact: Ann Koebler
ann.koebler@springer.com
49-622-148-78414
Springer

Physicists study fast-moving electrons in graphene as a model laboratory for massless particles

A team of physicists from Europe and South Africa showed that electrons moving randomly in graphene can mimic the dynamics of particles such as cosmic rays, despite travelling at a fraction of their speed, in a paper about to be published in EPJ B.

Andrey Pototsky and colleagues made use of their knowledge of graphene, which is made of a carbon layer, one atom thick, and packed in a honeycomb lattice pattern. In such material the interaction of electrons with atoms changes the effective mass of the electrons. As a result, the energy of electrons in graphene becomes similar to the photon energy.

Therefore, electrons in graphene can be regarded as behaving like cosmic rays, which belong to a family known as ultra-relativistic particles, even though their actual velocity is one hundred times lower than the speed of light.

The authors employed the classical equations used to describe random motionso-called Brownian motionto study the dynamics of electrons within the confines of their graphene mini-laboratory. They considered different graphene chip geometries and subjected them to changing conditions that affect the way these electrons diffuse through the material, such as temperature and electric field strength.

Going one step further, the authors were able to rectify electron fluctuations and to control the electron motion itself, from an unusual chaotic type of motion to a periodic movement, by varying the electric field.

Future work would experimentally demonstrate how variation of the temperature can be used positively to enhance the performance of graphene chips by gaining a greater control over electron transport. Such graphene mini-labs could also ultimately help us to understand the dynamics of matter and anti-matter in cosmic rays.

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Reference:

A. Pototsky, F. Marchesoni, F. V. Kusmartsev, P. Hanggi, and S. E. Savel'ev, Relativistic Brownian motion on a graphene chip, European Physical Journal B (2012) 85: 356, DOI: 10.1140/epjb/e2012-30716-7

For more information, please visit www.epj.org

The full-text article is available for journalists on request.


[ Back to EurekAlert! ] [ | E-mail | Share Share ]

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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.


Graphene mini-lab [ Back to EurekAlert! ] Public release date: 31-Oct-2012
[ | E-mail | Share Share ]

Contact: Ann Koebler
ann.koebler@springer.com
49-622-148-78414
Springer

Physicists study fast-moving electrons in graphene as a model laboratory for massless particles

A team of physicists from Europe and South Africa showed that electrons moving randomly in graphene can mimic the dynamics of particles such as cosmic rays, despite travelling at a fraction of their speed, in a paper about to be published in EPJ B.

Andrey Pototsky and colleagues made use of their knowledge of graphene, which is made of a carbon layer, one atom thick, and packed in a honeycomb lattice pattern. In such material the interaction of electrons with atoms changes the effective mass of the electrons. As a result, the energy of electrons in graphene becomes similar to the photon energy.

Therefore, electrons in graphene can be regarded as behaving like cosmic rays, which belong to a family known as ultra-relativistic particles, even though their actual velocity is one hundred times lower than the speed of light.

The authors employed the classical equations used to describe random motionso-called Brownian motionto study the dynamics of electrons within the confines of their graphene mini-laboratory. They considered different graphene chip geometries and subjected them to changing conditions that affect the way these electrons diffuse through the material, such as temperature and electric field strength.

Going one step further, the authors were able to rectify electron fluctuations and to control the electron motion itself, from an unusual chaotic type of motion to a periodic movement, by varying the electric field.

Future work would experimentally demonstrate how variation of the temperature can be used positively to enhance the performance of graphene chips by gaining a greater control over electron transport. Such graphene mini-labs could also ultimately help us to understand the dynamics of matter and anti-matter in cosmic rays.

###

Reference:

A. Pototsky, F. Marchesoni, F. V. Kusmartsev, P. Hanggi, and S. E. Savel'ev, Relativistic Brownian motion on a graphene chip, European Physical Journal B (2012) 85: 356, DOI: 10.1140/epjb/e2012-30716-7

For more information, please visit www.epj.org

The full-text article is available for journalists on request.


[ Back to EurekAlert! ] [ | E-mail | Share Share ]

?


AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.


Source: http://www.eurekalert.org/pub_releases/2012-10/s-gm103112.php

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