By Allison Kubo Hutchison
In late 1940, Debeers Diamond began using the slogan “Diamonds are forever” to promote diamond engagement rings. What they didn’t know is that this could be true regarding quantum mechanics. Diamonds are made of pure carbon, with the atoms arranged in a tetrahedral shape in a strong, rigid crystal structure. They are the hardest known material, which means that they have a hardness of 70-150 GPa in the Vickers hardness test. This hardness is inherited from its strong crystal structure and is exactly what diamond is forever.
Green indicates carbon atoms within a diamond crystal structure. With nitrogen, a void can form, basically an empty hole in the crystal. NIST, Nitrogen vacancy center, marked as public domain.
One of the main goals of this work is to use diamonds, especially the NV site, as the basis for the quantum computer. The defects are incredibly small, the size of two atoms, but are also incredibly sensitive to magnetic fields. If you change the magnetic field by up to a nanotesla, the luminosity of the NV site changes, indicating a change in spin. Very small sensors could be made in this way. Imagine a quantum computer with diamond circuits in which every defect in the nanometer range stores a “qubit”, a quantum computer bit. However, to take advantage of this we need to create incredibly precise defects in synthetic diamonds. Diamonds that were once valued for their beauty and clarity are now valued for their flaws.