Zhang Wei, Govorov Alexander O, Bryant Garnett W
Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701-2979, USA.
Phys Rev Lett. 2006 Oct 6;97(14):146804. doi: 10.1103/PhysRevLett.97.146804. Epub 2006 Oct 4.
Modern nanotechnology opens the possibility of combining nanocrystals of various materials with very different characteristics in one superstructure. Here we study theoretically the optical properties of hybrid molecules composed of semiconductor and metal nanoparticles. Excitons and plasmons in such a hybrid molecule become strongly coupled and demonstrate novel properties. At low incident light intensity, the exciton peak in the absorption spectrum is broadened and shifted due to incoherent and coherent interactions between metal and semiconductor nanoparticles. At high light intensity, the absorption spectrum demonstrates a surprising, strongly asymmetric shape. This shape originates from the coherent internanoparticle Coulomb interaction and can be viewed as a nonlinear Fano effect which is quite different from the usual linear Fano resonance.
现代纳米技术开启了将具有截然不同特性的各种材料的纳米晶体组合在一个超结构中的可能性。在此，我们从理论上研究了由半导体和金属纳米颗粒组成的混合分子的光学性质。这种混合分子中的激子和等离激元会发生强耦合并展现出新颖的性质。在低入射光强度下，由于金属和半导体纳米颗粒之间的非相干和相干相互作用，吸收光谱中的激子峰变宽并发生位移。在高光强度下，吸收光谱呈现出令人惊讶的、强烈不对称的形状。这种形状源自纳米颗粒间的相干库仑相互作用，可被视为一种非线性法诺效应，它与通常的线性法诺共振有很大不同。
