  It is illustrated that semiconductor quantum dots (QDs) embedded into an
insulating matrix connected with metallic electrodes and some vacuum space can
lead to significant thermal rectification effect. A multilevel Anderson model
is used to investigate the thermal rectification properties of the multiple-QD
junction. The charge and heat currents in the tunneling process are calculated
via the Keldysh Green's function technique. We show that pronounced thermal
rectification and negative differential thermal conductance (NDTC) behaviors
can be observed for the multiple-QD junction with asymmetrical tunneling rates
and strong interdot Coulomb interactions.
