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arXiv · 1908.10837

Origins of electromagnetic anisotropy in monolayer black phosphorus

Pengke Li
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Abstract

Contrary to empirical observations, lowest-order $k\cdot\hat{p}$ theory predicts that monolayer black phosphorus ("phosphorene") is completely immune to zigzag-polarized optical excitation at the bandgap energy. Using symmetry arguments, we derive a $2\times2$ Hamiltonian under the $k\cdot\hat{p}$ formalism including higher-order corrections, which is used to show that the experimentally-measured band-gap transition with zigzag polarization is dominated by the third order $k\cdot\hat{p}$ perturbation in the interband optical matrix element, whereas the effects of spin-orbit interaction are negligible in this material, consistent with a trivial orbital diamagnetic contribution to the $\textit{g}$-factor.

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Pengke Li. 2019-08-29. Origins of electromagnetic anisotropy in monolayer black phosphorus. https://doi.org/10.1103/physrevb.100.205418

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