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1、I will explain why Quantum Error Correction is necessary to unlock the full potential of quantum computing,as well as recent progress towards meaningful fault tolerant demonstrations.Quantum Error CorrectionQuantum Error CorrectionAlexandra Moylett,Senior Quantum Scientist,RiverlaneQuantum Error Cor
2、rectionSPECIAL FOCUS:QUANTUMLarge-scale Quantum ApplicationsUnderstanding physical systemsDrug discoveryMaterial sciences105 qubits,1013 quantum gatesEquation solvingComputational fluid dynamicsPlasma physics100s of qubits,1015 quantum gatesIvanov et al.,Phys.Rev.Research 5,013200(2023)Dalzell et al
3、.,arXiv:2310.03011Image credit:braintruffle on YouTubeErrors accumulateDecoherenceErasureLeakageMeasurement flipsHow bad are errors?0.1%error,one gateOne qubit99.9%chance no errorHow bad are errors?0.1%error,100 gatesOne qubit90.4%chance no errorHow bad are errors?0.1%error,100 gates50 qubits1%chanc
4、e no errorThe repetition codeCorrect errors classically by repeating data0L=0001L=111Errors corrected by taking majority voteBeneficial at low error probabilitiesMeasurements change a quantum state Quantum states cannot be cloned.A quantum“repetition”codeInitialise many qubits in the|0 stateMeasure
5、pairs to check for bit flipsResult:one logical qubit immune to bit flipsNot immune to other errors Further protectionKitaev,arXiv:quant-ph/9707021Further protectionRepeat qubits in 2D gridKitaev,arXiv:quant-ph/9707021Further protectionRepeat qubits in 2D gridAdd two-qubit measurements on sidesKitaev
6、,arXiv:quant-ph/9707021Further protectionRepeat qubits in 2D gridAdd two-qubit measurements on sidesAdd four-qubit measurements in middleKitaev,arXiv:quant-ph/9707021Further protectionRepeat qubits in 2D gridAdd two-qubit measurements on sidesAdd four-qubit measurements in middleResult:the surface c
7、odeKitaev,arXiv:quant-ph/9707021Repeat qubits in 2D gridAdd two-qubit measurements on sidesAdd four-qubit measurements in middleResult:the surface codeFurther protectionKitaev,arXiv:quant-ph/9707021Quantum error correction developmentsPreserving a logical qubitEstimates for large applicationsGoogle
8、Quantum AI,Nature 614,676-681(2023)Blunt et al.,J.Chem.Theory Comput.18,7001-7023(2022)Next steps in quantum error correctionFault-tolerant quantum logicEstimates for small-scale applicationsGehr et al.,arXiv:2312.11605Blunt,Geher and Moylett,Phys.Rev.Research 6,013325(2024)Logical Hadamard gateHydr
9、ogen moleculeHow can quantum error correction help you?For quantum hardware manufacturers:what noise affects your qubits?For end users:what applications for early fault-tolerant quantum computers do you find interesting?For data centre developers:how can we split the quantum/classical resources in fault-tolerant quantum computing?Additional informationOur research:https:/ error correction zoo:https:/errorcorrectionzoo.org/Quantum Error Correction:An Introductory Guide:https:/arxiv.org/abs/1907.11157Thank you!