论文标题
低维过渡金属二分法中的柔性诱导的铁电性
Flexo-induced ferroelectricity in low dimensional transition metal dichalcogenides
论文作者
论文摘要
我们开发了一种Landau类型理论，用于描述低维过渡金属二核苷（TMDS）中极性现象，该理论专门探讨了由于自发弯曲而引起的极化的柔性起源和由于与底物的相互作用而引起的反转对称性破坏。我们考虑由于挠性耦合与自发表面波纹的应变梯度和表面诱导的压电性的应变梯度，我们考虑了自发的平面外极化的出现。执行的计算证明，平面外的自发极化起源于波纹TMD中的柔韧性效应，可通过不均匀的电场进行双态和可逆。相反，外部电场无法逆转，这是由不合适的应变和对称敏感的表面诱导的压电耦合引起的自发极化。特别注意线性介电敏感性和增益因子的光谱分析，这对于通过表面增强的振动光谱学观察低维TMD的极性现象至关重要。
We developed a Landau type theory for the description of polar phenomena in low-dimensional transition metal dichalcogenides (TMDs), specifically exploring flexoelectric origin of the polarization induced by a spontaneous bending and by inversion symmetry breaking due to the interactions with substrate. We consider the appearance of the spontaneous out-of-plane polarization due to the flexoelectric coupling with the strain gradient of the spontaneous surface rippling and surface-induced piezoelectricity. Performed calculations proved that the out-of-plane spontaneous polarization, originated from flexoelectric effect in a rippled TMD, is bistable and reversible by a non-uniform electric field. In contrast, the spontaneous polarization induced by a misfit strain and symmetry-sensitive surface-induced piezoelectric coupling, cannot be reversed by an external electric field. The special attention is paid to the spectral analysis of the linear dielectric susceptibility and gain factor, which enhancement is critically important for the observation of the polar phenomena in low-dimensional TMDs by the surface-enhanced vibrational spectroscopy.
