Optical excitation of Josephson plasma solitons in a cuprate superconductor
Optical excitation of Josephson plasma solitons in a cuprate superconductor
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DOI：
10.1038/nmat3580
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发表时间：
2013-06-01
期刊：
影响因子：
41.2
通讯作者：
Cavalleri, A.
中科院分区：
文献类型：
--
作者：
Dienst, A.;Casandruc, E.;Cavalleri, A.
约瑟夫森等离子体波是沿铜酸盐超导体平面传播的线性电磁模式，由层间隧道超电流维持。对于强电磁场，当超电流接近临界值时，电动力学变得高度非线性。约瑟夫森等离子体孤子（JPS）是在此状态下预测的呼吸激发，束缚涡旋-反涡旋对，相干传播而无色散。我们使用调谐到 2-THz 约瑟夫森等离子体共振的红外自由电子激光器发出的强窄带辐射，通过实验证明了 La1.84Sr0.16CuO4 中 JPS 的激发。 JPS 变得可观察到，因为它在等离子共振正下方的不透明光谱区域中产生了一个透明窗口。携带磁通量的孤子的光学控制可能会在太赫兹频率等离子体激元、信息存储和传输以及高温超导操纵中带来新的应用。
Josephson plasma waves are linear electromagnetic modes that propagate along the planes of cuprate superconductors, sustained by interlayer tunnelling supercurrents. For strong electromagnetic fields, as the supercurrents approach the critical value, the electrodynamics become highly nonlinear. Josephson plasma solitons (JPSs) are breather excitations predicted in this regime, bound vortex-antivortex pairs that propagate coherently without dispersion. We experimentally demonstrate the excitation of a JPS in La1.84Sr0.16CuO4, using intense narrowband radiation from an infrared free-electron laser tuned to the 2-THz Josephson plasma resonance. The JPS becomes observable as it causes a transparency window in the opaque spectral region immediately below the plasma resonance. Optical control of magnetic-flux-carrying solitons may lead to new applications in terahertz-frequency plasmonics, in information storage and transport and in the manipulation of high-T-c superconductivity.