†Physics Department, University of California-San Diego, La Jolla, California 92093, United States.
‡Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117546.
Nano Lett. 2015 Aug 12;15(8):4859-64. doi: 10.1021/acs.nanolett.5b00125. Epub 2015 Jul 20.
We characterized plasmon propagation in graphene on thin films of the high-κ dielectric PbZr0.3Ti0.7O3 (PZT). Significant modulation (up to ±75%) of the plasmon wavelength was achieved with application of ultrasmall voltages (< ±1 V) across PZT. Analysis of the observed plasmonic fringes at the graphene edge indicates that carriers in graphene on PZT behave as noninteracting Dirac Fermions approximated by a semiclassical Drude response, which may be attributed to strong dielectric screening at the graphene/PZT interface. Additionally, significant plasmon scattering occurs at the grain boundaries of PZT from topographic and/or polarization induced graphene conductivity variation in the interior of graphene, reducing the overall plasmon propagation length. Lastly, through application of 2 V across PZT, we demonstrate the capability to persistently modify the plasmonic response of graphene through transient voltage application.
我们研究了在高介电常数 PbZr0.3Ti0.7O3（PZT）薄膜上的石墨烯中的等离激元传播。通过在 PZT 上施加超小电压（< ±1 V），实现了等离子体波长的显著调制（高达 ±75%）。对在石墨烯边缘观察到的等离子体条纹的分析表明，PZT 上的石墨烯中的载流子表现为非相互作用的狄拉克费米子，由半经典的 Drude 响应近似，这可能归因于石墨烯/PZT 界面处的强介电屏蔽。此外，在 PZT 的晶粒边界处发生了显著的等离子体散射，这是由于石墨烯内部的形貌和/或极化诱导的石墨烯电导率变化引起的，从而缩短了整体等离子体传播长度。最后，通过在 PZT 上施加 2 V，我们证明了通过瞬态电压施加来持续改变石墨烯的等离子体响应的能力。
