2011/02/22 by S. V. Kuplevakhsky, A. N. Omelyanchouk, Yuriy Yerin +1 · 40 citations
Materials Science · Physics and Astronomy · #Condensed matter physics #Dimensionless quantity #Ginzburg–Landau theory #Iron-based superconductors research #Mesoscopic physics #Metastability #Nonlinear system #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Soliton #Superconductivity #Superconductivity in MgB2 and Alloys #Winding number #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1063/1.3660216
published in Low Temperature Physics 37(8), 667-677 (American Institute of Physics) · 15 pages, 3 figures
arxiv created 2011/02/22 · openalex publication_date 2011/08/01 · arxiv updated 2012/09/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In the framework of the Ginzburg-Landau approach, we present a self-consistent theory of specific soliton states in mesoscopic (thin-walled) two-band-superconducting cylinders in external parallel magnetic fields. Such states arise in the presence of “Josephson-type” interband coupling, when phase winding numbers are different for each component of the superconducting order parameter. We evaluate the Gibbs free energy of the system up to second-order terms in a certain dimensionless parameter ɛ≈Lm/Lk≪1, where Lm and Lk are the magnet and kinetic inductance, respectively. We derive the complete set of exact soliton solutions. These solutions are thoroughly analyzed from the viewpoint of both local and global (thermodynamic) stability. In particular, we show that rotational-symmetry-breaking caused by the formation of solitons gives rise to a zero-frequency rotational mode. Although soliton states prove to be thermodynamically metastable, the minimal energy gap between the lowest-lying single-soliton states and thermodynamically stable zero-soliton states can be much smaller than the magnetic Gibbs free energy of the latter states, provided that intraband “penetration depths” differ substantially and interband coupling is weak. The results of our investigation may apply to a wide class of mesoscopic doubly-connected structures exhibiting two-band superconductivity.