Title: Theory of Photocurrent and High-Harmonic Generation with Chiral Fermions Show Chinese title

Title: 手性费米子的光电流与高次谐波生成理论

Abstract: We theoretically discover possible dc-current induction and high-harmonic generation from photodriven chiral fermions in B20-type semimetals irradiated with circularly polarized light as nonlinear optical responses with several unconventional properties. First, we find multiple sign changes of the induced bulk dc photocurrent as a function of light parameters, which is ascribed to the nature of asymmetric photon-dressed bands in chiral systems. Moreover, we observe a parity-dependent directivity of high-harmonic generation where the odd- and even-order harmonics have intensities only in directions perpendicular and parallel to the polarization plane, respectively, which can be understood from dynamical symmetry of the present photodriven chiral systems. Show Chinese abstract

Abstract: 我们理论发现，在圆偏振光照射下，B20型半金属中的光驱动手性费米子可能产生直流电流感应和高次谐波生成，作为具有若干非典型特性的非线性光学响应。 首先，我们发现产生的体直流光电流的符号随光参数的变化而多次改变，这归因于手性系统中不对称光 dressed 带的特性。 此外，我们观察到高次谐波生成的宇称依赖方向性，其中奇数阶和偶数阶谐波的强度分别仅存在于与偏振平面垂直和平行的方向上，这可以从当前光驱动手性系统的动力学对称性来理解。