Microscopic description of intermediate mixed state in superconductors between the first and second types

Physical Review B: Condensed Matter and Materials Physics. 2024. Vol. 110. No. 5. Article 054502.

Vyacheslav D. Neverov, Alexander E. Lukyanov, Andrey V. Krasavin, Arkady A. Shanenko, Mihail D. Croitoru, Vagov A.

It has long been known that superconductors in the crossover between superconductivity types I and II exhibit
an intermediate mixed state (IMS) with exotic flux configurations such as vortex clusters and chains. Achieving
a comprehensive microscopic description of the vortex configurations within this intertype region has proven
elusive until now due to the large computational demands involved. We have addressed this long-standing
problem by presenting microscopic calculations of the IMS configurations. Our calculations, performed at zero
temperature, reveal key features of the IMS, including the formation of vortex clusters and the multivortex nature
of interactions between vortices. The obtained boundaries of the IT domain reproduce existing experimental
observations remarkably well. Also, the results match earlier findings obtained using the perturbation theory in
the vicinity of the critical temperature.

Keywords: intermediate mixed state, промежуточное смешанное состояние

Publication based on the results of: Properties of quantum metamaterials with competing ordering types (2024)