Magnetotransport phenomena in terahertz and dc driven Dirac fermion systems

该项目旨在为最近在太赫兹和直流驱动的狄拉克费米子系统中观察到的壮观的磁输运现象建立一个全面的理论，包括单层石墨烯和hgte基拓扑绝缘体的螺旋表面状态。该项目研究了太赫兹、霍尔场和声子诱导的磁振荡，它们在强驱动的非扰动状态下的非线性相互作用和演化，零电阻状态下向非平衡畴相过渡的条件，以及回旋加速器共振及其二次谐波（X2峰）的共振太赫兹响应。发展的理论将解释狄拉克费米子材料特有的效应。特别地，非平凡的贝里相在非线性输运和多光子过程中的作用将被研究。计划中的理论研究，以及在雷根斯堡、麻省理工学院、维也纳和新西伯利亚正在进行的相关实验，应该为二维电子系统的基本光电和输运特性提供深入的见解，并在其技术设计和功能方面取得重要进展。

This project aims to develop a comprehensive theory for spectacular magnetotransport phenomena recently observed in THz and dc driven Dirac fermion systems including monolayer graphene and helical surface states of HgTe-based topological insulators. The project addresses the THz-, Hall field-, and phonon-induced magnetooscillations, their nonlinear interplay and evolution in the non-perturbative regimes of strong driving, conditions of transition to nonequilibrium domain phases in zero resistance states, as well as the resonant THz response at the cyclotron resonance and its second harmonics (X2 peak). The developed theory will account for effects specific to Dirac fermion materials. In particular, the role of the nontrivial Berry phase in the nonlinear transport and multiphoton processes will be studied. The planned theoretical studies, along with the ongoing related experiments in Regensburg, MIT, Wien, and Novosibirsk, should provide deep insights into fundamental optoelectronic and transport properties of 2D electron systems and lead to important advances in their technological design and functionalities.