000886007 001__ 886007
000886007 005__ 20210130010559.0
000886007 0247_ $$2doi$$a10.18154/RWTH-2020-08026
000886007 0247_ $$2Handle$$a2128/26023
000886007 037__ $$aFZJ-2020-04228
000886007 041__ $$aen
000886007 1001_ $$0P:(DE-Juel1)167543$$aWillsch, Madita$$b0$$eCorresponding author
000886007 245__ $$aStudy of quantum annealing by simulating the time evolution of flux qubits$$f - 2020-01-31
000886007 260__ $$bRWTH Aachen University$$c2020
000886007 300__ $$aVIII, 163 pages
000886007 3367_ $$2DataCite$$aOutput Types/Dissertation
000886007 3367_ $$2ORCID$$aDISSERTATION
000886007 3367_ $$2BibTeX$$aPHDTHESIS
000886007 3367_ $$02$$2EndNote$$aThesis
000886007 3367_ $$0PUB:(DE-HGF)11$$2PUB:(DE-HGF)$$aDissertation / PhD Thesis$$bphd$$mphd$$s1604325748_30548
000886007 3367_ $$2DRIVER$$adoctoralThesis
000886007 500__ $$aDOI: 10.18154/RWTH-2020-08026
000886007 502__ $$aDissertation, RWTH Aachen University, 2020$$bDissertation$$cRWTH Aachen University$$d2020$$o2020-07-07
000886007 520__ $$aIn this thesis, we study the operation of existing quantum annealers by simulating the real-time dynamics of two coupled flux qubits based on SQUIDs (superconducting quantum interference devices) during quantum annealing processes. We investigate two aspects. First, we study the influence of the higher energy levels which are neglected when deriving the qubit Hamiltonian from the superconducting circuit model including the tunable coupler. Second, we investigate the influence of an environment on the qubit system during quantum annealing. For the latter, we examine two different models for the environment, a generic spin bath and non-interacting two-level systems. For simulating the dynamics, we use the Suzuki-Trotter product-formula algorithm to solve the time-dependent Schrödinger equation numerically. We find that the higher energy levels as well as the presence of the tunable coupler have little influence on the performance of the quantum annealing process for most of the investigated problem instances, suggesting that the two-level approximation works very well. However, we find that for a particular class of instances, the results of the SQUID model and the qubit model show certain deviations. Additionally, we perform experiments on the D-Wave 2000Q quantum annealer. Our study of the two models for the environment suggests that the model of non-interacting two-level systems is better suited to describe the data obtained from the real device than the generic spin bath model.
000886007 536__ $$0G:(DE-HGF)POF3-511$$a511 - Computational Science and Mathematical Methods (POF3-511)$$cPOF3-511$$fPOF III$$x0
000886007 536__ $$0G:(DE-Juel1)PHD-NO-GRANT-20170405$$aPhD no Grant - Doktorand ohne besondere Förderung (PHD-NO-GRANT-20170405)$$cPHD-NO-GRANT-20170405$$x1
000886007 588__ $$aDataset connected to DataCite
000886007 773__ $$a10.18154/RWTH-2020-08026
000886007 8564_ $$uhttps://juser.fz-juelich.de/record/886007/files/thesis_willsch.pdf$$yOpenAccess
000886007 8564_ $$uhttps://juser.fz-juelich.de/record/886007/files/thesis_willsch.pdf?subformat=pdfa$$xpdfa$$yOpenAccess
000886007 909CO $$ooai:juser.fz-juelich.de:886007$$pdnbdelivery$$pdriver$$pVDB$$popen_access$$popenaire
000886007 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)167543$$aForschungszentrum Jülich$$b0$$kFZJ
000886007 9131_ $$0G:(DE-HGF)POF3-511$$1G:(DE-HGF)POF3-510$$2G:(DE-HGF)POF3-500$$3G:(DE-HGF)POF3$$4G:(DE-HGF)POF$$aDE-HGF$$bKey Technologies$$lSupercomputing & Big Data$$vComputational Science and Mathematical Methods$$x0
000886007 9141_ $$y2020
000886007 915__ $$0StatID:(DE-HGF)0510$$2StatID$$aOpenAccess
000886007 920__ $$lyes
000886007 9201_ $$0I:(DE-Juel1)JSC-20090406$$kJSC$$lJülich Supercomputing Center$$x0
000886007 980__ $$aphd
000886007 980__ $$aVDB
000886007 980__ $$aUNRESTRICTED
000886007 980__ $$aI:(DE-Juel1)JSC-20090406
000886007 9801_ $$aFullTexts