We show that a ferromagnetic (F) slab with the in-plane magnetization sandwiched between two superconducting (S) films experiences strong demagnetization effect due to the Meissner screening of the stray magnetic field by superconductors. In the extreme case, the transition of the S film from normal to the superconducting state can switch the demagnetization factor from 0 to 1, which is in a sharp contrast with the S/F bilayers where such transition affects the magnetic field inside the F film only slightly. The giant demagnetization effect is shown to be qualitatively robust against the decreasing superconducting film thickness and may provide a hint toward the explanation of the anomalously large ferromagnetic resonance frequency shift recently observed for the S/F/S structures [Golovchanskiy et al., Phys. Rev. Appl. 14, 024086 (2020)].

中文翻译：

---

超导薄膜引起的巨大退磁效应

我们表明，由于超导体对杂散磁场的迈斯纳屏蔽，具有夹在两个超导 (S) 膜之间的面内磁化强度的铁磁 (F) 板经历了强烈的退磁效应。在极端情况下，S 膜从正常状态到超导状态的转变可以将退磁因子从 0 切换到 1，这与 S/F 双层形成鲜明对比，这种转变影响 F 膜内部的磁场只是轻微。巨大的退磁效应被证明对超导薄膜厚度的减小具有定性的鲁棒性，并且可能为解释最近观察到的 S/F/S 结构异常大的铁磁共振频移提供了暗示 [Golovchanskiy等人。，物理。牧师申请 14 , 024086 (2020)]。