Anisotropic energy transfer near multi-layer black phosphorus

Abstract Energy transfer (ET) between quantum emitters is a key process for many scientific domains and technological applications, and can be influenced by strategic placement of appropriate materials in the vicinity. However, all explored conventional isotropic materials lacks directional control over this process. Here, we show that multilayered black phosphorus (bP), a novel anisotropic two-dimensional material, can simultaneously dramatically boost and directionally control ET rates in the near-field regime. We find that bP exhibits a critical thickness above which the ET rates increase by several orders of magnitude compared to vacuum. Moreover, we demonstrate that bP can manipulate the ET in specific in-plane directions due to its strong in-plane anisotropy. Our results build the framework and provide fundamental insights into the mechanisms of ET near anisotropic materials, and open up new possibilities for designing and optimizing ET-based devices, systems and applications.