  Negative differential thermal resistance (NDTR) in approximate graphene
nanoribbons (GNRs) is investigated from one dimension to three dimensions by
using classical molecular dynamics method. For single-layer GNRs, NDTR can not
be observed for very narrow GNRs (one dimension), NDTR appears when the width
of GNRs increases (two dimensions). However, NDTR disappears gradually on
further increasing the width. For multiple-layer GNRs, when the number of the
layers increases, GNRs becomes from two-dimensional system to three-dimensional
system, NDTR regime reduces and eventually disappears. In addition, when the
length of GNRs increases, NDTR regime also reduces and vanishes in the
thermodynamic limit. These effects may be useful for designing thermal devices
where NDTR plays an important role.
