arXiv:1702.07122 [cond-mat.mes-hall]AbstractReferencesReviewsResources
Current in molecular junctions: Effects of system-reservoir coupling
Hari Kumar Yadalam, Upendra Harbola
Published 2017-02-23Version 1
We study the effect of system reservoir coupling strength on the current flowing through quantum junctions. We consider two simple double quantum dot configurations coupled to two external fermionic reservoirs and calculate the net current flowing between the two reservoirs. The net current is partitioned into currents carried by the eigenstates of the system and by the coherences induced between the states due to coupling with the leads. We find that current carried by populations is always positive whereas current carried by coherences may be negative. This results in a non-monotonic dependence of the net current on the coupling strength. We find that in certain cases, the net current can vanish at large couplings due to cancellation between currents carried by the states and the coherences. These results provide new insights into the non-trivial role of system-reservoir couplings on electron transport through quantum dot junctions.