Intermittent superconductivity in mesoscopic thin-film rings

• Published in: Physica. C, Superconductivity Vol. 483; pp. 8 - 12
• Main Authors: Shi, Liang-Ma, Liu, Lian-zhong, Wang, Xiang-xian, Zhu, Ren-yi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 14.12.2012; Elsevier
• Subjects: Boundary conditions; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical field (superconductivity); Devices; Exact sciences and technology; Intermittent superconductivity; Mesoscopic and nanoscale systems; Mesoscopic superconducting ring; Phase diagram; Phase diagrams; Physics; Properties of type I and type II superconductors; Superconducting films and low-dimensional structures; Superconductivity; Thin films; Thin-film ring; Intermittent superconductivity; Mesoscopic superconducting ring; Thin-film ring; Phase diagram; External fields; Superconducting thin films; Phase diagrams; Ginzburg-Landau theory; Superconductivity; Boundary conditions; Critical field; Quantum size effect; Phenomenological model; Rings; Mesoscopic systems
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2012.07.015

► We give that the phase diagrams of intermittent superconductivity and of the critical fields. ► The superconducting critical field shows quantum size effect when the ring is small. ► The field is irrelevant to the inner radius when it is much larger than the arm width of the ring. ► The intermittent superconductivity can be tuned by the surrounding medium, which is useful for designing SQUID-type devices. Intermittent superconductivity for mesoscopic thin-film rings is investigated by the phenomenological Ginzburg–Landau theory with the de Gennes boundary condition. Phase diagram for intermittent superconductivity vs lateral size of ring is given in the presence of an external applied field. The intermittent superconductivity is found to only exist in small rings. The superconducting critical field shows quantum size effect when the ring is small. But the field is irrelevant to the inner radius when it is much larger than the arm width of the ring. Finally, we show that the intermittent superconductivity can be tuned by the surrounding medium, which is useful for designing SQUID-type devices.