▎ 摘　　要

The thermal conductance of the width modulated graphene nanoribbons is investigated using the fourth nearest neighbor force constant method along with the Landauer formula. The method for thermal conductance reduction is examined. Although the thermal conductance of width modulated ribbons is even lower than that of narrow graphene nanoribbons (GNRs), our calculations show that removing atoms from a corner of the wide part of modulated ribbons further reduces the thermal conductance. This observation is a result of symmetry destruction. The thermal conductance reduction increases with the number of removed atoms. However, if atoms are removed from two corners such that there is increased structural symmetry, the thermal conductance could increases. This indicates that symmetry has more influence on thermal conductance than the number of removed atoms. On the other hand, removing atoms from three corners causes additional asymmetry and reduces thermal conductance further. Our results indicate that in addition to introducing width modulation, engineering the shape of the wide part of GNRs could also reduce the thermal conductance significantly.