Problems are solved more quickly than with existing technology by computers that can utilise quantum physics' features. This is intriguing, but they have a significant obstacle in doing so.

Japanese researchers, who may have offered the solution, have shown that niobium nitride, a superconducting material, may be added to a nitride-semiconductor substrate to generate a flat, crystalline layer. It might be easy to create quantum qubits using this technique for use with conventional computing hardware.

Niobium nitride (NbNx) thin films can be formed directly on top of an aluminum nitride (AlN) layer, according to research from the Institute of Industrial Science at The University of Tokyo. At temperatures colder than 16 degrees above, niobium nitride can become superconducting. At temperatures lower than 16 degrees above absolute zero, niobium nitride can start to superconduct.

It can be used to build a superconducting qubit when it is placed in a Josephson junction. The crystal structures and electrical properties of NbNx thin films made on AlN template substrates were studied in relation to temperature. They showed that the atom spacing of the two materials was compatible enough to produce flat layers.

Atsushi Kobayashi, the first author and corresponding author, said: "We observed that a highly crystalline layer could grow at the interface because of the minor lattice mismatch between aluminum nitride and niobium nitride."

"X-ray diffraction was used to determine the NbNx's crystallinity, and atomic force microscopy was used to record the surface topology. The chemical makeup was also examined using X-ray photoelectron spectroscopy. The researchers demonstrated how the growth circumstances, particularly the temperature, affected the atom arrangement, nitrogen content, and electrical conductivity.

The two materials' structural closeness makes it easier to incorporate superconductors into semiconductor optoelectronic devices.

Further, for future quantum devices like Josephson junctions, the clearly defined interface between the wide bandgap AlN substrate and the superconducting NbNx is crucial. Single photon or electron detectors can be made out of thin, highly crystallin superconducting layers that are only a few nanometers thick.