D-Wave has developed a lower noise version of their D-Wave 2000Q processor and has made it available on-line via their Leap quantum cloud service. They indicated that this enhanced processor uses the same basic design as the 2000Q but uses different materials in its construction which improve the noise. In conjunction with their announcement, D-Wave also released a white paper that compares the performance of the enhanced processor with the previous version. The data show roughly a 25X improvement in solution time with the enhanced processor. The work on researching improved materials was part of D-Wave’s development efforts for their next generation platform and apparently they decided to try out this technology on the current generation D-Wave 2000Q design.
D-Wave has not publicly disclosed the specifics of the materials changes, but careful selection of materials is certainly one of the important activities for development teams in their quest to develop quantum computers with higher quality qubits. As an example of research performed by other organizations, it has been determined that silicon-based quantum chips can achieve better coherence times if they start with >99.9999% pure wafers containing the Si-28 isotope. Normal silicon wafers may only be comprised of about 92% Si-28 with the remainder being Si-29 and Si-30. While this would not matter in a classical semiconductor device, the pure Si-28 is preferred for quantum computers because this isotope lacks a nuclear spin and provides better coherence times. Both NIST and Intel have reported work to develop a supply of this purified silicon.