Microwave emission from superconducting vortices in Mo/Si superlattices.
Microwave emission from superconducting vortices in Mo/Si superlattices.
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DOI：
10.1038/s41467-018-07256-0
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发表时间：
2018-11-22
影响因子：
16.6
通讯作者：
Huth M
中科院分区：
文献类型：
--
作者：
Dobrovolskiy OV;Bevz VM;Mikhailov MY;Yuzephovich OI;Shklovskij VA;Vovk RV;Tsindlekht MI;Sachser R;Huth M
磁场中的大多数超导体都被量子化磁通涡流晶格穿透。在输运电流的存在下，导致涡旋穿过样品边缘，由于表面场的切向分量的连续性，预计会发射电磁波。然而，由于低辐射功率水平和涡旋运动缺乏相干性，迄今为止尚未观测到这种辐射。在这里，我们清楚地证明了电磁波从穿过超导体/绝缘体Mo/Si超晶格层的漩涡中发射。发射光谱由窄的谐波相关峰组成，可以通过直流偏置电流在GHz范围内进行精细调谐，也可以通过面内磁场值进行粗略调谐。我们的研究结果表明，超导体/绝缘体超晶格可以作为直流可调微波发生器，弥补传统射频振荡器和（亚）太赫兹发生器之间的频率差距，这依赖于约瑟夫森效应。当超导涡旋穿过样品边缘时，预计会发射电磁波，但到目前为止还没有观察到这种辐射。在这里，Dobrovolskiy等人证明了来自穿过Mo/Si超晶格层的涡旋的电磁辐射，其中发射光谱可以通过直流偏置电流和平面内磁场进行调谐。
Most of superconductors in a magnetic field are penetrated by a lattice of quantized flux vortices. In the presence of a transport current causing the vortices to cross sample edges, emission of electromagnetic waves is expected due to the continuity of tangential components of the fields at the surface. Yet, such a radiation has not been observed so far due to low radiated power levels and lacking coherence in the vortex motion. Here, we clearly evidence the emission of electromagnetic waves from vortices crossing the layers of a superconductor/insulator Mo/Si superlattice. The emission spectra consist of narrow harmonically related peaks which can be finely tuned in the GHz range by the dc bias current and, coarsely, by the in-plane magnetic field value. Our findings show that superconductor/insulator superlattices can act as dc-tunable microwave generators bridging the frequency gap between conventional radiofrequency oscillators and (sub-)terahertz generators relying upon the Josephson effect. Emission of electromagnetic waves is expected when superconducting vortices cross sample edges, but such a radiation has not been observed so far. Here, Dobrovolskiy et al. evidence the electromagnetic radiation from vortices crossing the layers of a Mo/Si superlattice, where the emission spectra can be tuned by dc bias current and coarsely by the in-plane magnetic field.
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影响因子：
8.6
作者：
Bulaevskii, L. N.;Chudnovsky, E. M.
通讯作者：
Chudnovsky, E. M.
影响因子：
8.6
作者：
KLEINER, R;STEINMEYER, F;MULLER, P
通讯作者：
MULLER, P
影响因子：
4
作者：
Dobrovolskiy, Oleksandr V.;Huth, Michael
通讯作者：
Huth, Michael
影响因子：
3.7
作者：
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通讯作者：
CLEM, JR
影响因子：
3.7
作者：
GOLOSOVSKY, M;DAVIDOV, D;SCHIEBER, M
通讯作者：
SCHIEBER, M