A Japanese firm with its roots in the jewelry industry, working alongside academic researchers, has developed a new way to mass produce 2-inch diamond wafers. Importantly, these ‘Kenzan Diamonds’ are of high enough purity to be useful in applications such as quantum computing. According to the source, a single one of these 2-inch diamond wafers can be used to store the equivalent of a billion Blu-Ray discs.

Adamant Namiki Precision Jewelry Co., Ltd collaborated on this diamond wafer mass production technology with Saga University in Kyushu. Previous diamond wafers with the requisite purity for quantum computing applications were severely limited in size. According to the source, it previously wasn’t possible to grow them larger than a 4mm square. Previous attempts to grow 2-inch wafers (~55mm diameter) resulted in levels of nitrogen impurities that rendered the wafers of little or no use to the computing industry.

The mass production breakthrough appears to come from the application of following technique. Diamonds are grown on a sapphire substrate coated with an iridium film, using the principle of ‘step flow growth’, rather than using diamond micro-needle seeding. The substrates used by the new technique and the stepped structure allow the growth of the diamond under high temperatures and pressures, without any stress cracks upon cool-down. This method of wafer growth also minimizes the absorption of nitrogen, so it is beneath 3 billionths of a percent.

The size and low-nitrogen nature of the new wafers makes them useful for quantum storage applications. Using a 2-inch diamond wafer for quantum storage facilitates the storing of up to a billion Blu-Ray discs full of data. It is also equivalent to the amount of data transmitted by mobile networks in a typical day. From our calculations, this means a single diamond disc can store up to 25