373 research outputs found
Tuning critical field, critical current, and diode effect of narrow thin-film superconductors through engineering inhomogeneous Pearl length
We explore critical field and critical current behavior in inhomogeneous
narrow thin-film superconducting strips. Formulations are developed to
calculate free energy, critical field, and critical current for strips with
inhomogeneous Pearl length distributions. Our findings show that
inhomogeneities, specifically a shorter Pearl length in the middle of the
strip, significantly enhance the critical field . This has practical
implications for achieving complete flux expulsion. While narrow strips have
traditionally been considered the most effective approach to improve
and eliminate trapped vortices, our results suggest that engineered
inhomogeneities offer an alternative method to enhance and improve
flux expulsion without reducing strip width, providing greater design
flexibility for superconducting devices. Additionally, we find that for the
purpose of increasing the critical current, utilizing an inhomogeneous film
with a reduced Pearl length in the middle of the strip is more advantageous.
The enhancement in critical current arises from the current suppression effect
at the edges induced by the inhomogeneous distribution of superfluid density.
Furthermore, we demonstrate that an inhomogeneous film with a left-right
asymmetric Pearl length distribution enables control over the nonreciprocity of
the critical current, highlighting the potential of engineering inhomogeneous
Pearl length distributions to implement devices exhibiting the superconducting
diode effect. Our results provide concrete examples of how manipulating the
inhomogeneity of Pearl length can enhance the performance of superconducting
devices. Various methods such as doping nonuniform impurities or creating a
temperature gradient can be employed to implement an inhomogeneous Pearl length
distribution.Comment: 17 pages, 10 figure
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