Controlling phonon transport via its wave nature in nanostructures can achieve unique properties for various applications. In this paper, thermal conductivity of heterogeneous nano cross junction (hetero-NCJ) is studied through molecular dynamics simulation. It is found that decreasing or increasing the atomic mass of four side wires (SWs) severed as resonators, thermal conductivity of hetero-NCJ is enhanced, which is larger than that of homogeneous NCJ (homo-NCJ). Interestingly, by setting two SWs with larger atomic mass and other two SWs with smaller atomic mass, thermal conductivity of hetero-NCJ is abnormally decreased, which is even smaller than that of homo-NCJ. After further non-equilibrium Green’s function calculations, it is demonstrated that origin of increase is attributed to the hybridization broken induced by unidirectional shift of resonant modes. However, the decrease in thermal conductivity originates from hybridization complementation induced by bidirectional shift of resonant modes, which synergistically blocks phonon transport. This work provides a mechanism for further strengthening resonant hybridization effect and manipulating thermal transport.

通过纳米结构中的波性质控制声子传输可以为各种应用实现独特的特性。本文通过分子动力学模拟研究了异质纳米交叉结（hetero-NCJ）的热导率。发现减少或增加作为谐振器切断的四个侧线（SW）的原子质量，异质NCJ的热导率增强，其大于均质NCJ（homo-NCJ）的热导率。有趣的是，通过设置两个原子质量较大的SW和另外两个原子质量较小的SW，异质NCJ的热导率异常降低，甚至小于均质NCJ的热导率。经过进一步的非平衡格林函数计算，结果表明，增加的起源归因于共振模式的单向偏移引起的杂交破坏。然而，热导率的降低源于共振模式的双向偏移引起的杂化互补，这协同地阻止了声子传输。这项工作为进一步加强共振杂化效应和操纵热传输提供了一种机制。