Visualization of two-dimensional transition dipole moment texture in momentum space using high-harmonic generation spectroscopy
Visualization of two-dimensional transition dipole moment texture in momentum space using high-harmonic generation spectroscopy
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DOI：
10.1103/physrevb.103.l161406
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发表时间：
2020-06
期刊：
影响因子：
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通讯作者：
K. Uchida;V. Pareek;K. Nagai;K. Dani;K. Tanaka
中科院分区：
文献类型：
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作者：
K. Uchida;V. Pareek;K. Nagai;K. Dani;K. Tanaka
高度非线性光学现象可以提供对电子系统特性的了解，而这些特性很难通过传统的线性光学光谱来了解。特别是，晶体固体中的高次谐波产生（HHG）与原子气体中的高次谐波产生显着不同，它使我们能够获得电子特性，例如能带结构、贝里曲率和价电子密度。在这里，我们证明偏振分辨 HHG 测量可用于探测二维半导体动量空间中的跃迁偶极矩 (TDM) 纹理。 TDM 与电子系统的内部结构直接相关并控制光学特性。我们研究黑磷中的 HHG，它提供了一个简单的双能带系统，具有带隙共振激发。我们观察到 HHG 产率和偏振的独特晶体取向依赖性，并成功重建了与原子间键合结构相关的 TDM 织构。我们的结果证明了高次谐波光谱在探测晶体固体中的电子波函数方面的潜力。
Highly nonlinear optical phenomena can provide access to properties of electronic systems which are otherwise difficult to access through conventional linear optical spectroscopies. In particular, high harmonic generation (HHG) in crystalline solids is strikingly different from that in atomic gases, and it enables us to access electronic properties such as the band structure, Berry curvature, and valence electron density. Here, we show that polarization-resolved HHG measurements can be used to probe the transition dipole moment (TDM) texture in momentum space in two dimensional semiconductors. TDM is directly related to the internal structure of the electronic system and governs the optical properties. We study HHG in black phosphorus, which offers a simple two-band system, with bandgap resonant excitation. We observed a unique crystal-orientation dependence of the HHG yields and polarizations and succeeded in reconstructing the TDM texture related to the inter-atomic bonding structure. Our results demonstrate the potential of high harmonic spectroscopy for probing electronic wavefunctions in crystalline solids.