Terahertz radiation of jerk photocurrent

通过太赫兹发射光谱揭示手性多重半金属CoSi中非线性光电流的起源

Origin of nonlinear photocurrents in chiral multifold semimetal CoSi unveiled by terahertz emission spectroscopy

本研究通过太赫兹发射光谱分析手性多重半金属CoSi的非线性光电导，明确了位移、注入等多种非线性光电流的起源与数值，验证了相关拓扑物理机制，为中红外光伏应用与定量光伏光谱研究提供了支撑。

太赫兹磁光电流在拓扑绝缘体Bi$_2$Se$_3$中探测其拓扑表面态

Terahertz magneto-photocurrents in the topological insulator Bi$_2$Se$_3$ probe its topological surface states

通过太赫兹磁光电流研究拓扑绝缘体Bi$_2$Se$_3$中拓扑表面态的淬灭机制，揭示自旋-电荷转换过程。

Ultrafast polarization control of zero-bias photocurrent and terahertz emission in hybrid organic perovskites

Methylammonium lead iodide (MAPI) is a benchmark hybrid organic perovskite material, which is used for the low-cost, printed solar cells with over 20 percent power conversion efficiency. Yet, the nature of light-matter interaction in MAPI as well as the exact physical mechanism behind device operation is currently debated. Here we report room temperature, ultrafast photocurrent and freespace terahertz (THz) emission generation from unbiased MAPI induced by 150 fs light pulses. Polarization dependence of the observed photoresponse is consistent with the Bulk Photovoltaic Effect (BPVE) caused by…

Terahertz driven extremely nonlinear bulk photogalvanic currents in non-resonant conditions

We report on the generation of bulk photocurrents in materials driven by non-resonant bi-chromatic fields that are circularly polarized and co-rotating. The nonlinear photocurrents have a fully controllable directionality and amplitude without requiring carrier-envelope-phase stabilization or few-cycle pulses, and are generated with photon energies much smaller than the band gap (reducing heating in the photo-conversion process). We demonstrate with ab-initio calculations that the photocurrent generation mechanism is universal and arises in gaped materials (Si, diamond, MgO, hBN), in semi-meta…

通过栅极依赖太赫兹光电流谱揭示石墨烯莫尔超晶格的微带结构

Unveiling the Miniband Structure of Graphene Moiré Superlattices via Gate-dependent Terahertz Photocurrent Spectroscopy

本文提出栅极依赖太赫兹光电流谱技术，探测石墨烯莫尔超晶格微带结构中的避免带交叉和微小能隙，并揭示非共振增强响应与体光电流机制，为低噪声太赫兹探测提供新平台。

Chiral terahertz wave emission from the Weyl semimetal TaAs

As a fascinating topological phase of matter, Weyl semimetals host chiral fermions with distinct chiralities and spin textures. Optical excitations involving those chiral fermions can induce exotic carrier responses, and in turn lead to novel optical phenomena. Here, we discover strong coherent chiral terahertz emission from the Weyl semimetal TaAs and demonstrate unprecedented manipulation over its polarization on a femtosecond timescale. Such polarization control is achieved via the colossal ultrafast photocurrents in TaAs arising from the circular or linear photogalvanic effect. We unravel …