资源描述:
《大学物理实验报告 英文版》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、大学物理实验报告FerroelectricControlofSpinPolarizationABSTRACTAcurrentdrawbackofspintronicsisthelargepowerthatisusuallyrequiredformagneticwriting,incontrastwithnanoelectronics,whichrelieson“zero-current,”gate-controlledoperations.Effortshavebeenmadetocontrolthespin-relaxationrate,theCurietemperature,o
2、rthemagneticanisotropywithagatevoltage,buttheseeffectsareusuallysmallandvolatile.Weusedferroelectrictunneljunctionswithferromagneticelectrodestodemonstratelocal,large,andnonvolatilecontrolofcarrierspinpolarizationbyelectricallyswitchingferroelectricpolarization.Ourresultsrepresentagianttypeofi
3、nterfacialmagnetoelectriccouplingandsuggestalow-powerapproachforspin-basedinformationcontrol.Controllingthespindegreeoffreedombypurelyelectricalmeansiscurrentlyanimportantchallengeinspintronics(1, 2).Approachesbasedonspin-transfertorque(3)haveprovenverysuccessfulincontrollingthedirectionofmagn
4、etizationinaferromagneticlayer,buttheyrequiretheinjectionofhighcurrentdensities.Anidealsolutionwouldrelyontheapplicationofanelectricfieldacrossaninsulator,asinexistingnanoelectronics.Earlyexperimentshavedemonstratedthevolatilemodulationofspin-basedpropertieswithagatevoltageappliedthroughadiele
5、ctric.Notableexamplesincludethegatecontrolofthespin-orbitinteractioninIII-Vquantumwells(4),theCurietemperature TC (5),orthemagneticanisotropy(6)inmagneticsemiconductorswithcarrier-mediatedexchangeinteractions;forexample,(Ga,Mn)Asor(In,Mn)As.Electricfield–inducedmodificationsofmagneticanisotrop
6、yatroomtemperaturehavealsobeenreportedrecentlyinultrathinFe-basedlayers(7, 8).Anonvolatileextensionofthisapproachinvolvesreplacingthegatedielectricbyaferroelectricandtakingadvantageofthehystereticresponseofitsorderparameter(polarization)withanelectricfield.Whencombinedwith(Ga,Mn)Aschannels,for
7、instance,aremanentcontrolof TC overafewkelvinwasachievedthroughpolarization-drivenchargedepletion/accumulation(9, 10),andthemagneticanisotropywasmodifiedbythecouplingofpiezoelectricityandmagnetostriction(11, 12).Indicationsofanelectrica