Violation of magnetic flux conservation by superconducting nanorings
Abstract
The behavior of magnetic flux in ring-shaped finite-gap superconductors is explored from the view-point of the flux-conservation theorem, which states that under the variation of an external magnetic field ‘the magnetic flux through the ring remains constant’ (see, e.g., Landau and Lifshitz 1960 Electrodynamics of Continuous Media (New York: Pergamon)). Our results, based on the time-dependent Ginzburg–Landau equations and COMSOL modeling, made it clear that in the general case this theorem is incorrect. While for macroscopic rings the corrections are small, for micro- and nanorings they become rather substantial. The physical reasons behind this effect are discussed. The dependence of flux deviation on ring size, bias temperature and the speed of external flux evolution is explored. The detailed structure of flux distribution inside the ring opening, as well as the electric field distribution inside the ring wire cross section, are revealed. Our results and the developed finite element modeling approach can assist in elucidating various fundamental topics in superconducting nanophysics and in the advancement of nanosize superconducting circuits prior to time-consuming and costly experiments.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 17, 2022
- Source ID
- 10.1088/1361-6668/ac4174
Entities
People
- Armen Gulian
- Gurgen Melkonyan
- Iris Mowgood
- Rajendra Dulal
- Sara Chahid
- Serafim Teknowijoyo
Organizations
- Office of Naval Research