简介:Thispaperinvestigatestheoreticallytheelectronictransmissionspectraofthethreeterminalpyrenemolecularbridgeandthequantumcurrentdistributiononeachbondbythetight-bindingmodelbasedonnonequilibriumGreen'sfunctionandthequantumcurrentdensityapproach,inwhichoneπmolecularorbitalistakenintoaccountpercarbonatomwhentheenergylevelsandHOMO-LUMOgapareobtained.Thetransmissionspectrashowthattheelectronictransmissionofthethreeterminalpyrenemolecularbridgedependsobviouslyontheincidentelectronicenergyandthepyreneeigenenergy.Thesymmetricalandoscillationpropertiesofthetransmissionspectraareillustrated.Anovelplus-minusenergyswitchingfunctionisfound.Thequantumcurrentdistributionshowsthattheloopcurrentsinsidethepyreneareinduced,andsomebondcurrentsaremuchlargerthantheinputandtheoutputcurrents.Thereasonswhytheloopcurrentsandthelargerbondcurrentsareinducedarethephasedifferenceoftheatomicorbitsandthedegeneracyofthemolecularorbits.ThecalculationsillustratethatthequantumcurrentdistributionsareingoodagreementwithKirchhoffquantumcurrentconservationlaw.