  The nonlinear thermoelectric properties of serially coupled quantum dots
(SCQDs) embedded in a nanowire connected to metallic electrodes are
theoretically studied in the Coulomb blockade regime. We demonstrate that the
electron heat current of SCQDs exhibit a direction-dependent behavior (heat
rectification) in an asymmetrical structure in which the electron Coulomb
interactions are significant. The phonon thermal conductivity of the nanowire
is also calculated, which is used to estimate the phonon heat current. Finally,
we discuss how to reduce phonon heat current to allow observation of electron
heat rectification behavior in the SCQD junction system in low temperature
regime ($\approx 3 K$).
