Effect of Bias Step on the IV Curve in DoubleBarrier.pdf

CHIN．PHYS．LETT Vo1．23，No．4(2006)960 EffectofBiasSteponthe —VCurveinDouble-BarrierA1GaAs／GaAs／AlGaAs Resonant—TunnellingDevices DAIZhen—Hong(戴振宏)2十 NIJun(倪军) DepartmentofPhysicsandKeyLaboratoryofAtomicandMolecularNanoscience，TsinghuaUniversity Beijing100084 DepartmentofPhysics，YantaiUniversity,Yantai264005 (Received8November2005) Weinvestigatethenon—equilibriumelectrontransportpropertiesofdouble—barrierAICaAs／GaAs／A1GaAsresonant— tunnellingdevicesinnonlinearbiasusingthetime—dependentsimulationtechnique．Itisfoundthatthebiasstep oftheexternaJbiasvoltageappliedonthedevicehasanimportanteffectonthe6halcurrent—voltagef一 curves．Theresultsshow thatdifferentbiasstepappliedon thedevicecanchanget血ebistablety,hysteresisand currentDlateaustructureoftheI— V CUrVe．Thecurrentplateauoccursonly inthecaseofsmallbiasstpe ．As thebiasstep increases，thisplateaustructuredisappears． PACS：7340．Gk，7321．Fg，73．23一b，73．50，-h W iththedevelopmentofthemolecularbeam epi— InthisLetter，usingthetime．dependentnumerical taxyfMBE1technique，thedouble—barrierresonant simulationtechnique，westudytheelectrontransport tunnellingnanodeviceshavebeenextensivelystudied propertyofanAlGaAs／GaAs／AlGaAsdouble—barrier —N目_】＼《。0_[一 ∞∞ 1【0 duetotheirpotentialdeviceapplicationsinvariousas— devicewhoseenergyband—profileisshownintheinset pects．Therehavebeenmanyimportantexperimental ofFig．1．W efind thatapartfrom theeffectofthe discoveriesinthiskindofconfinedsystems．【一 Now， deviceitself，thebiasstepappliedonthedeviceplays mostoftheexperimentalstudiesfoCUSon the elec— animporta