Title: Evanescent Optothermoelectric Trapping: Deeper Potentials at a Largescale Show Chinese title

Title: 倏逝光热电捕获：在大规模中的更深层次势能

Abstract: Surface plasmons (SP) and their mediated effects have been widely used to manipulate micro- and nanoscale objects of dielectric and metallic nature. In this work, we show how SP excitation can be used to induce thermofluidic and thermoelectric effects to manipulate colloidal dynamics on a large scale. In an evanescent plasmonic trap, temperature gradients induce fluid flow that can facilitate particle accumulation. However, large out-of-plane flows expel particles from the trap, resulting in a shallow trap potential. Here, we numerically demonstrate how adding thermoelectric fields can overpower the optical and hydrodynamic forces to achieve a stable nanoparticle assembly at low excitation powers. We calculate the corresponding optical, fluidic, and thermoelectric trapping forces and potentials. These potentials can be enabled without resonant SP excitation, which requires careful optical alignment. Thus, we explain the mechanism of how, despite weak optical intensities and forces, sufficient trapping force can be supplied via the evanescent optothermoelectric trap to obtain large-scale reversible nanoparticle assemblies, irrespective of their shape, size, or material. Show Chinese abstract

Abstract: 表面等离子体（SP）及其介导效应已被广泛用于操控介电和金属性质的微米和纳米尺度物体。 在本工作中，我们展示了如何利用SP激发来诱导热流体和热电效应，以在大范围内操控胶体动力学。 在倏逝等离子体陷阱中，温度梯度会引发流体流动，有助于粒子聚集。 然而，大的垂直方向流动会将粒子从陷阱中排出，导致陷阱势能较浅。 在这里，我们通过数值模拟展示如何添加热电场可以克服光学和水动力力，从而在低激发功率下实现稳定的纳米粒子组装。 我们计算了相应的光学、流体和热电捕获力和势能。 这些势能可以在不进行共振SP激发的情况下实现，这需要仔细的光学对准。 因此，我们解释了即使光学强度和力较弱，通过倏逝光热电陷阱仍可提供足够的捕获力，以获得大规模可逆的纳米粒子组装，而不论其形状、大小或材料。