Nonlinear terahertz spectroscopy of Higgs mode in s-wave superconductors
Nonlinear terahertz spectroscopy of Higgs mode in s-wave superconductors
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DOI：
10.1088/1402-4896/aa5327
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发表时间：
2017-01
期刊：
影响因子：
2.9
通讯作者：
Ryusuke Matsunaga;R. Shimano
中科院分区：
文献类型：
--
作者：
Ryusuke Matsunaga;R. Shimano
我们回顾了我们最近的实验，超快动力学的s波超导体Nb 1-xTixN的非线性太赫兹（THz）光谱。用强单周期太赫兹脉冲在超导带隙边缘瞬时注入准粒子后，观察到超导序参量的振幅模--Higgs模的自由振荡.研究了强交流驱动场作用下，光子能量调谐到超导带隙以下时序参量的超快非平衡动力学。希格斯模式和电磁场之间的共振非线性相互作用被揭示，表现为从超导体的有效的太赫兹三次谐波产生。
We review our recent experiments of ultrafast dynamics in s-wave superconductors Nb1-xTixN by using nonlinear terahertz (THz) spectroscopy. The free oscillation of the Higgs mode, i.e. the amplitude mode of the superconducting order parameter, is observed after instantaneous injection of quasiparticles at the superconducting gap edge by an intense monocycle THz pulse. The ultrafast nonequilibrium dynamics of the order parameter under the strong AC driving field with the photon energy tuned below the superconducting gap is also investigated. A resonant nonlinear interaction between the Higgs mode and the electromagnetic field is revealed, as manifested by an efficient THz third-harmonic generation from the superconductor.