Electromagnetic proximity effect in planar superconductor-ferromagnet structures
Electromagnetic proximity effect in planar superconductor-ferromagnet structures
复制标题
平面超导铁磁体结构中的电磁邻近效应
作者：
S. Mironov;A. Mel’nikov;A. Buzdin;A. Buzdin
研究表明，在邻近耦合超导-铁磁体结构中，铁磁体中库珀对的扩散会引起强烈的逆电磁现象，即磁场从铁磁体向超导体的长程转移.与先前研究的超导表面层自旋极化引起的逆邻近效应相反，上述逆电动效应的特征长度为伦敦穿透深度的数量级，其通常远大于超导相干长度。即使在没有铁磁体杂散场的情况下，也会出现相应的自发电流，并且是由S/F界面附近的磁化矢量势产生的，并且在纳米S/F器件的设计中应该考虑它们。类似于著名的Aharonov-Bohm效应，所讨论的现象可以被视为矢量势在量子物理中的作用的表现。
The spread of Cooper pairs in a ferromagnet in proximity coupled superconductor-ferromagnet structures is shown to cause a strong inverse electromagnetic phenomenon, namely, the long-range transfer of the magnetic field from the ferromagnet to the superconductor. Contrary to the previously investigated inverse proximity effect resulting from the spin polarization of a superconducting surface layer, the characteristic length of the above inverse electrodynamic effect is of the order of the London penetration depth, which usually is much larger than the superconducting coherence length. The corresponding spontaneous currents appear even in the absence of the stray field of the ferromagnet and are generated by the vector-potential of magnetization near the S/F interface, and they should be taken into account in the design of nanoscale S/F devices. Similarly to the well-known Aharonov-Bohm effect, the discussed phenomenon can be viewed as a manifestation of the role of vector potential in quantum physics.