Nitrogen-vacancy centers in diamonds could be used to construct vital components for quantum computers. But hitherto it has been impossible to read optically written information from such systems electronically. Using a graphene layer, a team of scientists headed by Professor Alexander Holleitner of the Technische Universität München (TUM) has now implemented just such a read unit.
Natural diamonds always contain defects. The most researched defects are nitrogen-vacancy centers comprising a nitrogen atom and a vacancy. These might serve as highly sensitive sensors or as register components for quantum computers. However, until now it has not been possible to extract the optically stored information electronically.
TUM researchers have now devised just such a methodology for reading the stored information in diamond nitrogen vacancy centers. The technique builds on a direct transfer of energy from nitrogen-vacancy centers in nanodiamonds to a directly neighboring graphene layer.
Non-radiative energy transfer
When laser light shines on a nanodiamond, a light photon raises an electron from its ground state to an excited state in the nitrogen-vacancy center. “The system of the excited electron and the vacated ground state can be viewed as a dipole,” says Professor Alexander Holleitner. “This dipole, in turn, induces another dipole comprising an electron and a vacancy in the neighboring graphene layer.”
In contrast to the approximately 100 nanometer large diamonds, in which individual nitrogen-vacancy centers are insulated from each other, the graphene layer is electrically conducting. Two gold electrodes detect the induced charge, making it electronically measureable.
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Laboratory set-up measuring the interaction between graphene and nano-diamonds with implanted nitrogen-vacancy centers.
Credit: Astrid Eckert / TUM
Nature Nanotechnology - Ultrafast electronic readout of diamond nitrogen-vacancy centres coupled to graphene
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Natural diamonds always contain defects. The most researched defects are nitrogen-vacancy centers comprising a nitrogen atom and a vacancy. These might serve as highly sensitive sensors or as register components for quantum computers. However, until now it has not been possible to extract the optically stored information electronically.
TUM researchers have now devised just such a methodology for reading the stored information in diamond nitrogen vacancy centers. The technique builds on a direct transfer of energy from nitrogen-vacancy centers in nanodiamonds to a directly neighboring graphene layer.
Non-radiative energy transfer
When laser light shines on a nanodiamond, a light photon raises an electron from its ground state to an excited state in the nitrogen-vacancy center. “The system of the excited electron and the vacated ground state can be viewed as a dipole,” says Professor Alexander Holleitner. “This dipole, in turn, induces another dipole comprising an electron and a vacancy in the neighboring graphene layer.”
In contrast to the approximately 100 nanometer large diamonds, in which individual nitrogen-vacancy centers are insulated from each other, the graphene layer is electrically conducting. Two gold electrodes detect the induced charge, making it electronically measureable.
Laboratory set-up measuring the interaction between graphene and nano-diamonds with implanted nitrogen-vacancy centers.
Credit: Astrid Eckert / TUM
Nature Nanotechnology - Ultrafast electronic readout of diamond nitrogen-vacancy centres coupled to graphene
Read more »
