Physicists from NUST MISIS, Moscow State Pedagogical University, HSE University, National Research University MPEI, and Skoltech have found what disrupts quantum states in thin films of titanium nitride. This material is used to create qubits and other elements of superconducting quantum devices.
Researchers compared different electron scattering mechanisms and found an unexpected result. Electron-electron interaction explains about 5% of the observed effect, and scattering by crystal lattice vibrations — less than 10%.
At the same time, the rate of phase coherence loss is almost independent of temperature. According to the scientists, this is consistent with another mechanism — magnetic scattering associated with a chaotic distribution of local magnetic moments.
Experiments showed that electron-electron interaction explains about 5% of the observed effect, and the contribution of electron-phonon scattering is less than 10%.
As the film thickness decreases, the density of magnetic defects increases. This indicates their location predominantly near the material's surface.
The discovery is important for the development of quantum electronics — even small surface defects can degrade the performance of superconducting devices. Scientists suggest separately controlling the surface condition and protecting it from oxidation.
Read more on the topic:
- Thin layer, big problem: Scientists from MISIS, RUDN, and RCTU reduced graphene resistance by almost 18 times
- New generation aluminum alloy developed by NUST MISIS scientists in collaboration with Spanish colleagues
- For laser technology and microelectronics: scientists at Ogarev Moscow State University found a way to control pores in metal coatings
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