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Abstract
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It is well known that future information technology relies upon electronic states other than charge,
through the feasibility of constructingspintronicandvalleytronicdevices.Themainchallengeinsuch
applications isthegenerationandcontrolofthecorrespondingstatecurrents.Thepresentpaperisthus
concerned withcharge,spinandvalleycurrentswhichintrinsicallydevelopinarmchairsilicene
nanoribbons (ASNs).InpursuingthisconsiderationthewellestablishedKuboformulaisemployed.
TakingthesymmetriesoftheASNintoaccount,weanalyzethestructureoftotalHamiltonianand
demonstratehowthematrixelementsalongwiththesummationsinvolvedinthesuitablyadopted
Kuboformula,maybeanalyticallycalculated.Theresultsso-obtainedalongwiththecorresponding
figures revealthatallthreecurrentsdevelopinastep-wisemanner.Theheights,indicatingajumpinthe
current, andtheplateaus,indicatingaconstantcurrent,areshowntobetunablebyadjustingthewidth
and/or thebuckledeffect.Moreover,wedemonstratethatforparticular(critical)widthsaninversionin
band gapsmayoccur,givingrisetoquantumphasetransitions.Morepracticalresultofthispaper,aswe
show,isthefactthattheASNcangeneratepurespin or valleycurrentunderspecific conditionsplaced
on thewidth,buckledeffectandFermienergy.Thematerialpresentedinthispaperthusprovidesnovel
means ofgenerationandcontrolofthecharge,spinandvalleycurrents.
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