Chu Hao, Kim Min-Jae, Katsumi Kota, Kovalev Sergey, Dawson Robert David, Schwarz Lukas, Yoshikawa Naotaka, Kim Gideok, Putzky Daniel, Li Zhi Zhong, Raffy Hélène, Germanskiy Semyon, Deinert Jan-Christoph, Awari Nilesh, Ilyakov Igor, Green Bertram, Chen Min, Bawatna Mohammed, Cristiani Georg, Logvenov Gennady, Gallais Yann, Boris Alexander V, Keimer Bernhard, Schnyder Andreas P, Manske Dirk, Gensch Michael, Wang Zhe, Shimano Ryo, Kaiser Stefan
Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany.
4th Physics Institute, University of Stuttgart, 70569, Stuttgart, Germany.
Nat Commun. 2020 Apr 14;11(1):1793. doi: 10.1038/s41467-020-15613-1.
In high-energy physics, the Higgs field couples to gauge bosons and fermions and gives mass to their elementary excitations. Experimentally, such couplings can be inferred from the decay product of the Higgs boson, i.e., the scalar (amplitude) excitation of the Higgs field. In superconductors, Cooper pairs bear a close analogy to the Higgs field. Interaction between the Cooper pairs and other degrees of freedom provides dissipation channels for the amplitude mode, which may reveal important information about the microscopic pairing mechanism. To this end, we investigate the Higgs (amplitude) mode of several cuprate thin films using phase-resolved terahertz third harmonic generation (THG). In addition to the heavily damped Higgs mode itself, we observe a universal jump in the phase of the driven Higgs oscillation as well as a non-vanishing THG above T. These findings indicate coupling of the Higgs mode to other collective modes and potentially a nonzero pairing amplitude above T.
在高能物理学中，希格斯场与规范玻色子和费米子耦合，并赋予它们的基本激发态质量。在实验中，这种耦合可以从希格斯玻色子的衰变产物中推断出来，即希格斯场的标量（振幅）激发。在超导体中，库珀对与希格斯场有密切的类比关系。库珀对与其他自由度之间的相互作用为振幅模式提供了耗散通道，这可能揭示有关微观配对机制的重要信息。为此，我们使用相位分辨太赫兹三次谐波产生（THG）来研究几种铜酸盐薄膜的希格斯（振幅）模式。除了严重阻尼的希格斯模式本身，我们还观察到驱动希格斯振荡相位的普遍跃变以及高于转变温度（T）时非零的三次谐波产生。这些发现表明希格斯模式与其他集体模式的耦合，并且可能在高于转变温度（T）时存在非零的配对振幅。
