Optical nonlinearities of excitons in monolayer MoS2
Optical nonlinearities of excitons in monolayer MoS2
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DOI：
10.1103/physrevb.97.165111
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发表时间：
2017-11
影响因子：
3.7
通讯作者：
D. Soh;C. Rogers;D. Gray;Eric Chatterjee;H. Mabuchi
中科院分区：
文献类型：
--
作者：
D. Soh;C. Rogers;D. Gray;Eric Chatterjee;H. Mabuchi
利用二次量子化的束缚和非束缚激子算符，计算了单层MoS2的激子态在面内光偏振下的线性和非线性光学极化率。光学选择规则是获得亲和性的关键。我们推导了单层MoS2中二次谐波产生的谷手性规则，发现三次谐波过程仅对线偏振光有效，而三阶双光子过程（光学克尔效应）对使用高阶激子态的圆偏振光有效。由于带隙和异常强的双光子三阶非线性的线性吸收的情况下，单层二硫化钼激子结构的相干非线性光子学的一个有前途的资源。
We calculate linear and nonlinear optical susceptibilities arising from the excitonic states of mono- layer MoS2 for in-plane light polarizations, using second-quantized bound and unbound exciton operators. Optical selection rules are critical for obtaining the susceptibilities. We derive the valley-chirality rule for the second harmonic generation in monolayer MoS2, and find that the third- harmonic process is efficient only for linearly polarized input light while the third-order two photon process (optical Kerr effect) is efficient for circularly polarized light using a higher order exciton state. The absence of linear absorption due to the band gap and the unusually strong two-photon third-order nonlinearity make the monolayer MoS2 excitonic structure a promising resource for coherent nonlinear photonics.