Thread-like diamonds may power quantum computing

Scientists have developed a way to mass-produce tiny diamond crystals shaped like needles and threads, which may power next generation of quantum computing.
Physicists from the Lomonosov Moscow State University in Russia have described structural peculiarities of micrometre-sized diamond crystals in needle- and thread-like shapes, and their interrelation with luminescence features and field electron emission efficiency.
Technological applications of diamonds significantly outweigh their popularity as jewelry, and are increasingly widespread in industry.
This is a motivation for researchers busy with elaboration of new diamond synthesis techniques.
One of the problems they have addressed is production of needle- and thread-like diamond crystals. Such shaping of original natural and synthetic diamonds is possible due to polishing in the same way as in jewelry production.

Other techniques include lithography and ion beam technologies, which help to separate fragments of desired shapes from large-sized crystals.

However, such cutting techniques are quite expensive, and not always practical.
The researchers of the current study propose a technology that makes possible the mass production of small diamond crystals (or crystallites) of needle- and thread-like shapes. Their first results were published seven years ago.
"The proposed technique involves determining formation of polycrystalline films from crystallites of elongate (columnar) shape," Alexander Obraztsov, professor at the Lomonosov Moscow State University.
For instance, ice on a surface of a lake often consists of such crystallites, which can be observed while melting," said Obraztsov.

Researchers have shown that low-quality diamond films consisting of separate, unconnected crystallites could be used for production of diamonds in the form of needle- or thread-like shapes.
In order to achieve this, it is necessary to heat such films in an oxygen-containing environment. When heated, a part of the film material begins oxidising and gasifies.
Due to the fact that diamond crystallite oxidation requires maximum temperature, it's possible to adjust the temperature so that all the material except these diamond crystallites is gasified.
This relatively simple technology combines production of polycrystalline diamond films with specific structural characteristics via heating in oxygen.

It enables mass production of diamond crystallites of various shapes.
The crystallites could be used, for instance, as high-hardness elements - cutters for high-precision processing, or indenters or probes for scanning microscopes.
The study was published in journal Scientific Reports.