Hu Huatian, Álvarez-Pérez Gonzalo, Otomalo Tadele Orbula, Ciracì Cristian
Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Via Barsanti 14, 73010 Arnesano, Italy.
ACS Photonics. 2024 Sep 19;11(11):4812-4817. doi: 10.1021/acsphotonics.4c01308. eCollection 2024 Nov 20.
We develop an efficient numerical model based on the semiclassical hydrodynamic theory for studying Kerr nonlinearity in degenerate electron systems such as heavily doped semiconductors. This model provides direct access to the electromagnetic responses of the quantum nature of the plasmons in heavily doped semiconductors with complex geometries, which is nontrivial for conventional frameworks. Using this model, we demonstrate nanoscale optical bistability at an exceptionally low-power threshold of 1 mW by leveraging Kerr-type hydrodynamic nonlinearities supported by the heavily doped semiconductor's free carriers. This high nonlinearity is enabled by a strong coupling between metallic gap plasmons and longitudinal bulk plasmons in the semiconductor due to quantum pressure. These findings offer a viable approach to studying Kerr-type nonlinearity and lay the groundwork for developing efficient and ultrafast all-optical nonlinear devices.
我们基于半经典流体动力学理论开发了一种高效数值模型，用于研究简并电子系统（如重掺杂半导体）中的克尔非线性。该模型可直接获取具有复杂几何形状的重掺杂半导体中量子性质的等离激元的电磁响应，这对于传统框架而言并非易事。利用该模型，我们通过利用重掺杂半导体自由载流子所支持的克尔型流体动力学非线性，在1 mW的极低功率阈值下演示了纳米级光学双稳性。由于量子压力，半导体中金属带隙等离激元和纵向体等离激元之间的强耦合实现了这种高非线性。这些发现为研究克尔型非线性提供了一种可行的方法，并为开发高效、超快的全光非线性器件奠定了基础。
