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arXiv 2104.09186cond-mat.mes-hallcond-mat.mtrl-sci
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双层石墨烯局域应变的Fano共振红外纳米成像

Fano resonance enabled infrared nano-imaging of local strain in bilayer graphene

Jing Du, Bosai Lyu, Wanfei Shan, Jiajun Chen, Xianliang Zhou, Jingxu Xie, Aolin Deng, Cheng Hu, Qi Liang, Guibai Xie, Xiaojun Li, Weidong Luo, Zhiwen Shi

摘要:

在纳米尺度下以高灵敏度检测局部应变仍然具有挑战性。在这里,我们报告的近场红外纳米成像的局部应变在双层石墨烯通过探测应变引起的声子频率的变化。作为一种非极性晶体,本征双层石墨烯在其横光学(TO)声子频率处具有很小的红外响应。所报道的局部应变的光学检测通过施加垂直电场来实现,该垂直电场打破两个石墨烯层的对称性并向石墨烯声子引入有限电偶极矩。激活的声子进一步与连续电子跃迁相互作用,产生强的Fano共振。由此产生的Fano共振具有非常尖锐的近场红外散射峰,这导致应变检测的异常灵敏度为~0.002%。我们的研究展示了第一个纳米尺度的近场Fano共振,提供了一种新的方式来探测非极性晶体中的高灵敏度的局部应变,并为研究应变诱导的丰富现象打开了令人兴奋的可能性。

英文摘要:

Detection of local strain at the nanometer scale with high sensitivity remains challenging. Here we report near-field infrared nano-imaging of local strains in bilayer graphene through probing strain-induced shifts of phonon frequency. As a non-polar crystal, intrinsic bilayer graphene possesses little infrared response at its transverse optical (TO) phonon frequency. The reported optical detection of local strain is enabled by applying a vertical electrical field that breaks the symmetry of the two graphene layers and introduces finite electrical dipole moment to graphene phonon. The activated phonon further interacts with continuum electronic transitions, and generates a strong Fano resonance. The resulted Fano resonance features a very sharp near-field infrared scattering peak, which leads to an extraordinary sensitivity of ~0.002% for the strain detection. Our studies demonstrate the first nano-scale near-field Fano resonance, provide a new way to probe local strains with high sensitivity in non-polar crystals, and open exciting possibilities for studying strain-induced rich phenomena.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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