Point defects in super-chilled diamonds may offer stable candidates for quantum computing bits

ScienceDaily (Oct. 13, 2011) — Diamond, nature's hardest known substance, is essential for our modern mechanical world -- drills, cutters, and grinding wheels exploit the durability of diamonds to power a variety of industries. But diamonds have properties that may also make them excellent materials to enable the next generation of solid-state quantum computers and electrical and magnetic sensors.

To further explore diamonds' quantum computing potential, researchers from the University of Science and Technology of China tested the properties of a common defect found in diamond: the nitrogen-vacancy (NV) center.

Consisting of a nitrogen atom impurity paired with a 'hole' where a carbon atom is absent from the matrix structure, the NV center has the potential to store information because of the predictable way in which electrons confined in the center interact with electromagnetic waves. The research team probed the energy level properties of the trapped electrons by cooling the diamonds to an extremely chilly 5.6 degrees Kelvin and then measuring the magnetic resonance and fluorescent emission spectra. The team also measured the same spectra at gradually warmer increments, up to 295 degrees Kelvin.

The results, as reported in the AIP's journal Applied Physics Letters, show that at temperatures below 100 Kelvin the electrons' transition energies, or the energies required to get from one energy level to the next, were stable. Shifting transition energies could make quantum mechanical manipulations tricky, so cooler temperatures may aid the study and development of diamonds for quantum computation and ultra-sensitive detectors, the authors write.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Institute of Physics, via EurekAlert!, a service of AAAS.

Journal Reference:

X.-D. Chen, C.-H. Dong, F.-W. Sun, C.-L. Zou, J.-M. Cui, Z.-F. Han, and G.-C Guo. Temperature dependent energy level shifts of nitrogen-vacancy centers in diamond. Applied Physics Letters, 2011

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

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Point defects in super-chilled diamonds may offer stable candidates for quantum computing bits

ScienceDaily (Oct. 13, 2011) — Diamond, nature's hardest known substance, is essential for our modern mechanical world -- drills, cutters, and grinding wheels exploit the durability of diamonds to power a variety of industries. But diamonds have properties that may also make them excellent materials to enable the next generation of solid-state quantum computers and electrical and magnetic sensors.

To further explore diamonds' quantum computing potential, researchers from the University of Science and Technology of China tested the properties of a common defect found in diamond: the nitrogen-vacancy (NV) center.

Consisting of a nitrogen atom impurity paired with a 'hole' where a carbon atom is absent from the matrix structure, the NV center has the potential to store information because of the predictable way in which electrons confined in the center interact with electromagnetic waves. The research team probed the energy level properties of the trapped electrons by cooling the diamonds to an extremely chilly 5.6 degrees Kelvin and then measuring the magnetic resonance and fluorescent emission spectra. The team also measured the same spectra at gradually warmer increments, up to 295 degrees Kelvin.

The results, as reported in the AIP's journal Applied Physics Letters, show that at temperatures below 100 Kelvin the electrons' transition energies, or the energies required to get from one energy level to the next, were stable. Shifting transition energies could make quantum mechanical manipulations tricky, so cooler temperatures may aid the study and development of diamonds for quantum computation and ultra-sensitive detectors, the authors write.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Institute of Physics, via EurekAlert!, a service of AAAS.

Journal Reference:

X.-D. Chen, C.-H. Dong, F.-W. Sun, C.-L. Zou, J.-M. Cui, Z.-F. Han, and G.-C Guo. Temperature dependent energy level shifts of nitrogen-vacancy centers in diamond. Applied Physics Letters, 2011

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Rainbows without pigments offer new defense against fraud

ScienceDaily (May 19, 2011) — Scientists from the University of Sheffield have developed pigment-free, intensely coloured polymer materials, which could provide new, anti-counterfeit devices on passports or banknotes due to their difficulty to copy.

The polymers do not use pigments but instead exhibit intense colour due to their structure, similar to the way nature creates colour for beetle shells and butterfly wings.

These colours were created by highly ordered polymer layers, which the researchers produced using block copoylmers (an alloy of two different polymers). By mixing block copolymers together, the researchers were able to create any colour in the rainbow from two non-coloured solutions.

This type of polymer then automatically organises itself into a layered structure, causing optical effects similar to opals. The colour also changes depending on the viewing angle. This system has huge advantage in terms of cost, processing and colour selection compared to existing systems.

The complexity of the chemistry involved in making the polymer means they are very difficult for fraudsters to copy, making them ideally suited for use on passports or banknotes.

The academics used Diamond Light Source, the UK's national synchrotron science facility in Oxfordshire, to probe the ordered, layered structures using high power X-rays. This helped them understand how the colours were formed, and how to improve the appearance.

Dr Andrew Parnell, from the University of Sheffield's Department of Physics and Astronomy, said: "Our aim was to mimic the wonderful and funky coloured patterns found in nature, such as Peacock feathers. We now have a painter's palette of colours that we can choose from using just two polymers to do this. We think that these materials have huge potential to be used commercially."

Professor Nick Terrill, Principal Beamline Scientist for I22, the Diamond laboratory used for the experiment, explained: "Small Angle X-ray Scattering is a simple technique that in this case has provided valuable confirmatory information. By using Diamond's X-rays to confirm the structure of the polymer, the group was able to identify the appropriate blends for the colours required, meaning they can now tailor the polymer composition accordingly."

The institutions involved in the research include the University of Sheffield, the University of Hull and Diamond Light Source in Oxfordshire.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Sheffield.

Journal Reference:

Andrew J. Parnell, Andrew Pryke, Oleksandr O. Mykhaylyk, Jonathan R. Howse, Ali. M. Adawi, Nicholas J. Terrill, J. Patrick A. Fairclough. Continuously tuneable optical filters from self-assembled block copolymer blends. Soft Matter, 2011; 7 (8): 3721 DOI: 10.1039/C0SM01320J

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Rainbows without pigments offer new defense against fraud

ScienceDaily (May 19, 2011) — Scientists from the University of Sheffield have developed pigment-free, intensely coloured polymer materials, which could provide new, anti-counterfeit devices on passports or banknotes due to their difficulty to copy.

The polymers do not use pigments but instead exhibit intense colour due to their structure, similar to the way nature creates colour for beetle shells and butterfly wings.

These colours were created by highly ordered polymer layers, which the researchers produced using block copoylmers (an alloy of two different polymers). By mixing block copolymers together, the researchers were able to create any colour in the rainbow from two non-coloured solutions.

This type of polymer then automatically organises itself into a layered structure, causing optical effects similar to opals. The colour also changes depending on the viewing angle. This system has huge advantage in terms of cost, processing and colour selection compared to existing systems.

The complexity of the chemistry involved in making the polymer means they are very difficult for fraudsters to copy, making them ideally suited for use on passports or banknotes.

The academics used Diamond Light Source, the UK's national synchrotron science facility in Oxfordshire, to probe the ordered, layered structures using high power X-rays. This helped them understand how the colours were formed, and how to improve the appearance.

Dr Andrew Parnell, from the University of Sheffield's Department of Physics and Astronomy, said: "Our aim was to mimic the wonderful and funky coloured patterns found in nature, such as Peacock feathers. We now have a painter's palette of colours that we can choose from using just two polymers to do this. We think that these materials have huge potential to be used commercially."

Professor Nick Terrill, Principal Beamline Scientist for I22, the Diamond laboratory used for the experiment, explained: "Small Angle X-ray Scattering is a simple technique that in this case has provided valuable confirmatory information. By using Diamond's X-rays to confirm the structure of the polymer, the group was able to identify the appropriate blends for the colours required, meaning they can now tailor the polymer composition accordingly."

The institutions involved in the research include the University of Sheffield, the University of Hull and Diamond Light Source in Oxfordshire.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Sheffield.

Journal Reference:

Andrew J. Parnell, Andrew Pryke, Oleksandr O. Mykhaylyk, Jonathan R. Howse, Ali. M. Adawi, Nicholas J. Terrill, J. Patrick A. Fairclough. Continuously tuneable optical filters from self-assembled block copolymer blends. Soft Matter, 2011; 7 (8): 3721 DOI: 10.1039/C0SM01320J

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here