分数量子霍尔效应中复合费米子边缘态的光谱学研究
Optical spectroscopy of composite fermion edge states in the fractional quantum Hall effect
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中文总结 AI 辅助
本研究利用复合费米子平均场框架，通过亚太赫兹光谱学探测分数量子霍尔效应样品的边缘态，其吸收峰特征可作为填充因子的指纹，为电子相互作用诱导的复合费米子有效质量提供直接光学探测手段。
中文摘要 AI 辅助
我们表明，分数量子霍尔效应样品中的边缘态可通过亚太赫兹光谱学进行选择性探测与激发。利用复合费米子（CF）平均场框架（该框架将强关联的分数量子霍尔问题映射为有效整数量子霍尔问题），我们计算了填充因子Jain序列的吸收光谱，包含体态与边缘态。CF边缘态吸收峰出现在毫米波至亚太赫兹范围，例如GaAs中B=10 T时为60-500 GHz，即相对于体态CF回旋频率发生蓝移，但远低于相同磁场下整数量子霍尔回旋频率的尺度。吸收光谱各系列中分辨出的峰数量对应填充的Lambda能级数目，可作为该分数的指纹。边缘附近的反演对称性破缺激活了体态中禁戒的光学跃迁，并在电偶极近似下实现了二阶非线性过程。光谱的绝对频率尺度由CF有效质量决定，该质量完全由电子-电子相互作用产生，因此吸收光谱为这种相互作用诱导质量提供了直接的光学探测手段。
英文摘要
We show that edge states in fractional quantum Hall effect samples can be selectively probed and excited with sub-terahertz optical spectroscopy. Using the composite fermion (CF) mean-field framework, which maps the strongly correlated fractional quantum Hall problem onto an effective integer quantum Hall problem, we calculate the absorbance spectrum for the Jain sequence of filling fractions including both bulk and edge states. The CF edge-state absorption peaks appear in the millimeter-wave to sub-terahertz range, e.g., 60-500 GHz at B = 10 T in GaAs, i.e. they are blueshifted with respect to the bulk CF cyclotron frequency but are well below the integer quantum Hall cyclotron frequency scale at the same magnetic fields. The number of resolved peaks in each series of the absorption spectrum counts the filled Lambda-levels and fingerprints the fraction. Inversion symmetry breaking near the edge activates optical transitions forbidden in the bulk and enables second-order nonlinear processes in electric-dipole approximation. The absolute frequency scale of the spectrum is set by the CF effective mass, which is generated entirely by electron-electron interactions, so the absorption spectrum provides a direct optical probe of this interaction-induced mass.
