Kvantový počítač

Overview

Quantumcomputer,simplyput,itisamachinethatcanrealizequantumcomputing,itisakindofmathematicalandlogicaloperationthroughthelawsofquantummechanics,processingandstoringinformationAbilitysystem.Itusesquantumstatesasthememoryunitandinformationstorageform,andusesquantumdynamicstoevolveasthebasisofquantumcommunicationandquantumcomputingforinformationtransmissionandprocessing.Inquantumcomputers,thesizeofvarioushardwarecomponentsreachestheorderofatomsormolecules.Aquantumcomputerisaphysicalsystemthatcanstoreandprocessinformationrepresentedbyqubits.

Justasthetraditionalcomputerrealizesthedistinctionbetween0and1throughtheon-offofthecircuitintheintegratedcircuit,anditsbasicunitisthesiliconchip,thequantumcomputeralsohasitsownbasicunit-quintessence(qubit).Quinbitisalsocalledqubit,itexpresses0or1throughthequantummechanicalsystemoftwostatesofquantum.Forexample,thetwoorthogonalpolarizationdirectionsofphotons,thespindirectionofelectronsinamagneticfield,orthetwodirectionsofnuclearspin,thetwodifferentenergylevelsofthequantuminanatom,orthespatialmodeofanyquantumsystem,etc.Theprincipleofquantumcomputingistoevolvethequantumstateinaquantummechanicalsystem.

Složení

Kvantové počítače, stejně jako mnoho počítačů, jsou složeny z velkého množství hardwaru a softwaru. Software zahrnuje kvantové goritmy, kvantové kódování atd. a hardware zahrnuje kvantové tranzistory a kvantové paměti, kvantový efektor atd.

Quantumtransistorsbreakthroughthephysicalenergylimitthroughthehigh-speedmovementofelectrons,therebyrealizingtheswitchingfunctionofthetransistor.Thiskindoftransistorcontrolstheswitchingspeedveryfast,andthetransistorhasamuchstrongercomputingpowerthanordinarychips.Theabilitytoadapttotheenvironmentalconditionsusedisverystrong,sointhefuturedevelopment,thetransistorisanindispensablepartofthequantumcomputer.Quantumstorageisastoragewithhighefficiencyinstoringinformation.Itcanassignvalues​​toanycalculationinformationinaveryshorttime.Itisanindispensablepartofaquantumcomputerandoneofthemostimportantpartsofaquantumcomputer.Theeffectorofaquantumcomputerisalarge-scalecontrolsystemthatcancontroltheoperationofvariouscomponents.Thesecomponentsoccupyamajorpositioninthedevelopmentofquantumcomputersandplayanimportantrole.

Principle

Quantumcomputerisakindofcomputerthatworksbasedonquantumtheory.Tracingbacktothesource,thecontinuousexplorationofreversiblemachineshaspromotedthedevelopmentofquantumcomputers.Quantumcomputerdevicesfollowthebasictheoryofquantumcomputing,processingandcalculatingquantuminformation,andrunningquantumalgorithms.In1981,PaulBenioffoftheAragonNationalLaboratoryintheUnitedStatesfirstproposedthebasictheoryofquantumcomputing.

1.Qubit

Thebasicunitofclassicalcomputerinformationisthebit.Abitisaphysicalsystemwithtwostates,representedby0and1.Inquantumcomputers,thebasicunitofinformationisaqubit,andtwoquantumstates│0>and│1>areusedtoreplacetheclassicalbitstates0and1.Comparedwithbits,qubitshaveuniquecharacteristicsofexistence.Theyexistintheformofsuperpositionoftwologicalstates,whichmeansthesuperpositionoftwocorrespondingquantumstatesof0and1.

2.Princip stavové superpozice

Thecoretechnologyofmodernquantumcomputermodelsistheprincipleofstatesuperposition,whichisabasicprincipleofquantummechanics.Inasystem,everypossiblewayofmovementiscalledastate.Inthemicrosystem,thestateofmotionofthequantumcannotbedetermined,anditisstatistical,contrarytothestateofmotiondeterminedbythemacrosystem.Thequantumstateisthestateofthemicroscopicsystem.

3. Kvantumanglement

Quantumentanglement:Whentwoparticlesareentangledwitheachother,thebehaviorofoneparticlewillaffectthestateoftheotherparticle.Thisphenomenonhasnothingtodowithdistance.Intheory,evenFarenoughapart,quantumentanglementcanstillbedetected.Therefore,whenthestateofoneofthetwoparticleschanges,thatis,whenthisparticleismanipulated,thestateoftheotherparticlewillalsochangeaccordingly.

4.Princip kvantového paralelismu

Quantumparallelcomputingisthemostcompellingadvancedtechnologythatquantumcomputerscansurpassclassicalcomputers.Quantumcomputersstorenumbersinexponentialform.Byincreasingthenumberofqubitsto300qubits,theycanstoremorenumbersthanalltheatomsintheuniverseandcanperformoperationsatthesametime.Thefunctioncalculationdoesnotusetheclassicalcyclicmethod,butcanbeobtaineddirectlythroughtheunitarytransformation,whichgreatlyreducestheworklossenergyandtrulyrealizesthereversiblecalculation.

Pokrok ve výzkumu

Počátkem 80. let Benioff jako první navrhl myšlenku kvantového počítání. Navrhl spustitelný kvantový Turingový stroj s klasickou analogií – prototyp kvantového počítače.

In1982,FeynmandevelopedBenioff’svision,proposingthatquantumcomputerscansimulateotherquantumsystems.Inordertosimulatequantummechanicalsystems,Feynmanproposedtheconceptofworkingcomputersinaccordancewiththelawsofquantummechanics,whichisconsideredtheearliestideaof​​quantumcomputers.

In1985,DavidDeutschofOxfordUniversityprovedthatanyphysicalprocesscanbewellsimulatedbyaquantumcomputerinprinciple,andproposedacomputersimulationbasedonquantuminterference,thatis,"quantumlogic".Thenewconceptof"gate"pointsoutthegeneralizationofquantumcomputersandthegenerationandcorrectionoferrorsinquantumcalculations.In-depthanalysisandresearchweredonebyZurek.Butbythemid-1980s,thisfieldofresearchwasleftoutforseveralreasons.Firstofall,becauseallquantumcomputermodelsatthetimeregardedquantumcomputersasanisolatedsystemthatdidnotinteractwiththeexternalenvironment,ratherthanactualmodels.Secondly,therearemanyconstraintsthatarenotconducivetotherealizationofquantumcomputers,suchasdecoherenceandthermalnoisepointedoutbyLandauer.Inaddition,quantumcomputersmaybeerror-proneandnoteasytocorrect.Finally,itisunclearwhetherquantumcomputerssolvemathematicalproblemsfasterthanclassicalcalculations.

In1994,Dr.PererShorofAT&Tdiscoveredaneffectivequantumalgorithmforfactorization.In1996,S.LoydprovedFeynman'sconjecture.Hepointedoutthatsimulatingtheevolutionofquantumsystemswillbecomeanimportantuseofquantumcomputers,whichcanbebuiltonthebasisofquantumTuringmachines.Sincethen,withtherapidprogressofinterdisciplinaryresearchbetweencomputerscienceandphysics,thetheoreticalandexperimentalresearchofquantumcomputinghasflourished.Asthedevelopmentofquantumcomputershasbeguntoenteranewera,governmentsandmajorcompanieshavealsoformulatedaseriesofresearchanddevelopmentplansforquantumcomputers.

Firstofall,theAdvancedResearchProjectsAgencyoftheUnitedStatesformulatedaresearchplannamed"QuantumInformationScienceandTechnologyDevelopmentPlan"inversion1.0andversion2.0inDecember2002andApril2004.TheplandetailsthemainstepsandtimetableforthedevelopmentofquantumcomputingintheUnitedStates.Intheplan,theUnitedStateswillstrivetodevelopacomputerwith10physicalqubitsin2007andacomputerwith50physicalqubitsby2012.TheUSArmyalsoplanstoequipitsweaponswithquantumcomputersby2020.

Europehasalsomadeactiveresearchanddevelopmentinquantumcomputingandquantumencryption.Theresearchonthedispersionandentanglementofdifferentquantumsystems(suchasatoms,ionsandresonances)aswellastheresearchonquantumalgorithmsandinformationprocessinginthefifthframeworkplanhasbeencompleted.Atthesametime,inthesixthframeworkplan,thefocuswillbeonresearchingquantumalgorithmsandencryptiontechnology,anditisexpectedthatby2008,ahighlyreliable,long-distancequantumdataencryptiontechnologywillbesuccessfullydeveloped.

Japanstartedafive-yearquantumcomputingandinformationprojectinOctober2000,focusingonthecomplexityofquantumcomputingandquantumcommunication,designingnewquantumalgorithms,developingrobustquantumcircuits,andfindingquantumTheusefulfeaturesofself-controlandthedevelopmentofquantumcomputingsimulators.

V roce 2007 kanadská společnost DWave úspěšně vyvinula 16kbitový kvantový počítač "Orion", který byl spuštěn v Kalifornii, USA a Vancouveru v Kanadě 13. února a 15. února 2008. Předveďte svůj kvantový počítač

OnNovember15,2009,theNationalInstituteofStandardsandTechnologyoftheUnitedStatesdevelopedaquantumcomputerthatcanprocesstwoquintessentialdata.

D-Wave,theworld’sfirstquantumcomputingcompany,announcedonJune22,2015thatithadbrokenthroughthe1000qubitbarrieranddevelopedanewprocessorwiththepreviousgenerationofqubits.TheD-Waveprocessorisabouttwiceasfast,andfarsurpassesthequbitsofDWaveoranyotherproductsdevelopedbyitspeers.

OnMarch6,2017,IBMannouncedthatitwilllaunchtheworld'sfirstcommercial"universal"quantumcomputingserviceIBMduringtheyear.IBMsaidthatthisserviceisequippedwiththeabilitytoaccessdirectlythroughtheInternet,andhasatransformativeroleindrugdevelopmentandvariousscientificresearches.Ithasbeguntorecruitconsumerusers.InadditiontoIBM,othercompaniessuchasIntel,Google,andMicrosoftarealsoexploringthefieldofpracticalquantumcomputers.

OnMay3,2017,theopticalquantumcomputerexperimentalprototypebuiltbythePanJianweiteamoftheChineseAcademyofScienceshassurpassedthatofearliercomputers.Inaddition,theChinesescientificresearchteamcompletedthemanipulationof10superconductingqubits,successfullybreakingtherecordofentanglementandcompletemeasurementofthesuperconductingqubitwiththelargestnumberofbitsintheworld.

OnJune18,2020,theChineseAcademyofSciencesannouncedthatPanJianwei,YuanZhensheng,etc.oftheUniversityofScienceandTechnologyofChinahavemadeimportantprogressinultra-coldatomicquantumcomputingandsimulationresearch-proposedtheoreticallyandrealizedexperimentallyOnthebasisofthenewmechanismofatomicdeepcooling,thesimultaneouspreparationof1250pairsofatomicentangledstateswithhighfidelitywasrealizedforthefirsttimeintheopticallattice,whichlaidthefoundationforthelarge-scalequantumcalculationandsimulationbasedontheultracoldatomicopticallattice.Thisresultwaspublishedonlineintheacademicjournal"Science"onthe19th.

OnDecember4,2020,theUniversityofScienceandTechnologyofChinaannouncedthatPanJianweiandothershadsuccessfullybuilta76-photonquantumcomputingprototype"NineChapters",anditonlytakes200secondstosolvethemathematicalalgorithmGaussianBosesampling,Andthefastestsupercomputerintheworldcurrentlytakes600millionyears.ThisbreakthroughmadeChinathesecondcountryintheworldtoachieve"quantumsuperiority".OnDecember4,theinternationalacademicjournal"Science"publishedtheresult,andthereviewersevaluateditas"amostadvancedexperiment"and"amajorachievement".

OnFebruary8,2021,HefeiBenyuanQuantumTechnologyCo.,Ltd.,aplatformforthetransformationofscientificandtechnologicalachievementsoftheKeyLaboratoryofQuantumInformationoftheChineseAcademyofSciences,releasedthequantumcomputeroperatingsystem"JinyuanSinan"withindependentintellectualpropertyrights.

OnJuly27,2021,theUniversityofTokyoandIBMofJapanannouncedthatcommercialquantumcomputershavebeenputintouse,whichisthefirsttimeinJapan.

Potíže

1. Kvantová dekoherence

Thecoherenceofquantumcomputingistheessenceofquantumparallelcomputing,butinactualsituations,qubitswillbeaffectedbytheoutsideworld.Theroleandinfluenceoftheenvironment,resultinginquantumentanglement.Quantumcoherenceiseasilydisturbedbyquantumentanglement,whichleadstoadecreaseinquantumcoherence,whichistheso-calleddecoherencephenomenon.Inpracticalapplications,thecontactbetweenthequbitandtheoutsideworldcannotbeavoided,andthecoherenceofthequantumisnoteasilymaintained.Therefore,theproblemofquantumdecoherenceisoneoftheimportantproblemsthatneedtobesolvedatpresent,anditssolutionwillaffectthefuturedevelopmentofquantumcomputerstoacertainextent.

2. Kvantumanglement

Asthesmallestparticle,quantumobeysthelawofquantumentanglement.Eveninspace,quantamaybeseparated,butthemutualinfluencebetweenquantaisunavoidable.Inbetween,quantumentanglementtechnologyisassociatedwiththefieldofquantuminformationtransmission.Inacertainsense,therapidcommunicationspeedbetweenquantaisusedtorealizethetransferofinformation.

3. Kvantumparalelní výpočet

Theuniqueparallelcomputingofquantumcomputersisanimportantpointthatclassicalcomputerscannotmatch.Itisalsoann-bitmemory,andthereisonlyoneresultstoredinaclassiccomputer.Buttheresultsstoredbythequantumcomputercanreach2n.Itsparallelcomputingnotonlyfarsurpassesthelatterinstoragecapacity,butalsohasafastreadingspeed,andmultiplereadingsandcalculationscanbeperformedatthesametime.Itispreciselytheimportanceofquantumparallelcomputing,anditseffectiveapplicationhasbecomeoneofthekeystothedevelopmentofquantumcomputers.

4. Kvantumuklonovatelnost

Quantumunclonabilityreferstotheprocessinwhichthereisnoreplicationofanyunknownquantumstate.Sinceitisnecessarytokeepthequantumstateunchanged,thereisnoquantumMeasurement,itisimpossibletoachievereplication.Forquantumcomputers,theerrorcorrectionapplicationsandreplicationfunctionsofclassicalcomputerscannotberealized.

Advantages

Quantumcomputershavepowerfulquantuminformationprocessingcapabilities.Forthecurrentmassiveamountofinformation,effectiveinformationcanbeextractedandprocessedtomakeitnewandusefulinformation.Theprocessingofquantuminformationfirstrequiresthestorageandprocessingofthequantumcomputer,andthenthequantumanalysisofthegiveninformation.Usingthismethodcanaccuratelypredictweatherconditions.Atpresent,theaccuracyrateofweatherconditionspredictedbycomputersis75%.However,theuseofquantumcomputersforpredictioncanfurtherincreasetheaccuracyrateandmakeitmoreconvenientforpeopletotravel.

Currentcomputersareusuallyattackedbyviruses,whichdirectlyleadtocomputerparalysisandthetheftofpersonalinformation.However,duetothequantumprincipleofnon-cloning,theseproblemswillnotexistinquantumcomputers.WhenusersusequantumYoucansafelysurftheInternetatyourcomputerwithoutfearofpersonalinformationleakage.Ontheotherhand,quantumcomputershavepowerfulcomputingcapabilitiesandcananalyzealargenumberofdifferentdataatthesametime,sotheycanaccuratelyanalyzefinancialtrendsinfinanceandplayagreatroleinavoidingfinancialcrises;theycanalsobeusedinbiochemicalresearch.Playagreatrole,cansimulatethecompositionofnewdrugs,anddevelopdrugsandchemicalproductsmoreaccurately,sothatthecostofdrugsandthepropertiesofdrugscanbeguaranteed.

Applicationprospects

Theoretically,quantumcomputershavetheabilitytosimulatearbitrarynaturalsystemsandarealsothekeytothedevelopmentofartificialintelligence.Duetothepowerfulcapabilitiesofquantumcomputersinparalleloperations,ithastheabilitytoquicklycompletecalculationsthatcannotbedonebyclassicalcomputers.Thisadvantagehashugeapplicationsinfieldssuchasencryptionanddeciphering.

(1)Weatherforecast:Ifweuseaquantumcomputertoanalyzealltheinformationatthesametimeandgettheresult,thenwecanknowtheprecisedirectionoftheweatherchange,therebyavoidingalotofeconomicloss.

(2)Drugdevelopment:Quantumcomputersalsohavegreatadvantagesforthedevelopmentofnewdrugs.Quantumcomputerscanmapoutthecompositionoftrillionsofmoleculesandchoosethemostpossiblemethodamongthem.Itwillincreasethespeedofpeopleinventingnewdrugsandbeabletoanalyzepharmacologymorepersonalized.

(3)Trafficscheduling:Quantumcomputerscanpredicttrafficconditionsbasedonexistingtrafficconditions,completein-depthanalysis,andperformtrafficschedulingandoptimization.

(4)Confidentialcommunication:Notonlyfortheaspectsofourlives,quantumcomputerswillnotbeabletodecipheranddecipherwithoutbeingdiscoveredduetoitsunclonableprincipleforencryptedcommunication.Eavesdropping,thisisdeterminedbythenatureofthequantumcomputeritself.