论文标题
在非常规超导体中，驱动的希格斯振荡和第三次谐波产生的理论
Theory of driven Higgs oscillations and third-harmonic generation in unconventional superconductors
论文作者
论文摘要
希格斯光谱法是一个新领域，其中分析了非平衡超导体中的希格斯模式，以获取有关基态的信息。观察到S-Wave超导体中HIGGS模式的一种实验设置是带有THZ光的周期性驾驶，如果驾驶频率与Higgs模式的能量匹配，则显示第三谐波发电（THG）信号的共鸣。我们得出驱动的差距振荡的表达式，以进行任意间隙对称性并计算THG响应。我们证明，如果驾驶频率与这些HIGGS模式的能量匹配，并且在我们的清洁限量分析中，则可能导致具有非平凡间隙对称性的超导体的可能的HIGGS模式，可能会导致额外的共鸣。通过此，我们表明对非常规超导体的实验允许检测其HIGGS模式。这为对现实系统的未来研究铺平了道路，包括其他功能，以了解非常规超导体的集体激发光谱。
Higgs spectroscopy is a new field in which Higgs modes in nonequilibrium superconductors are analyzed to gain information about the ground state. One experimental setup in which the Higgs mode in s-wave superconductors was observed is periodic driving with THz light, which shows resonances in the third-harmonic generation (THG) signal if twice the driving frequency matches the energy of the Higgs mode. We derive expressions of the driven gap oscillations for arbitrary gap symmetry and calculate the THG response. We demonstrate that the possible Higgs modes for superconductors with non-trivial gap symmetry can lead to additional resonances if twice the driving frequency matches the energy of these Higgs modes and we disentangle the influence of charge density fluctuations (CDF) to the THG signal within our clean-limit analysis. With this we show that THG experiments on unconventional superconductors allow for a detection of their Higgs modes. This paves the way for future studies on realistic systems including additional features to understand the collective excitation spectra of unconventional superconductors.
