000902637 001__ 902637 000902637 005__ 20240625095040.0 000902637 0247_ $$2doi$$a10.1103/PhysRevB.104.125116 000902637 0247_ $$2ISSN$$a1098-0121 000902637 0247_ $$2ISSN$$a2469-9977 000902637 0247_ $$2ISSN$$a0163-1829 000902637 0247_ $$2ISSN$$a0556-2805 000902637 0247_ $$2ISSN$$a1095-3795 000902637 0247_ $$2ISSN$$a1538-4489 000902637 0247_ $$2ISSN$$a1550-235X 000902637 0247_ $$2ISSN$$a2469-9950 000902637 0247_ $$2ISSN$$a2469-9969 000902637 0247_ $$2Handle$$a2128/29091 000902637 0247_ $$2altmetric$$aaltmetric:113726103 000902637 0247_ $$2WOS$$aWOS:000704419000001 000902637 037__ $$aFZJ-2021-04432 000902637 082__ $$a530 000902637 1001_ $$0P:(DE-Juel1)144464$$aZhang, Guoren$$b0 000902637 245__ $$aMagnetic superexchange couplings in Sr 2 IrO 4 000902637 260__ $$aWoodbury, NY$$bInst.$$c2021 000902637 3367_ $$2DRIVER$$aarticle 000902637 3367_ $$2DataCite$$aOutput Types/Journal article 000902637 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article$$bjournal$$mjournal$$s1637647633_26757 000902637 3367_ $$2BibTeX$$aARTICLE 000902637 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000902637 3367_ $$00$$2EndNote$$aJournal Article 000902637 520__ $$aWe investigate the magnetic couplings in Sr2IrO4 in the Mott-insulating picture, combining density-functional theory, dynamical mean-field theory, and many-body perturbation theory. We first determine the form of the jeff=1/2 pseudospin via the local-density-approximation + dynamical mean-field theory approach. Next we study the magnetic interactions in the strong-to-intermediate coupling regime. To this end, we calculate the superexchange pseudospin tensors Γ1, Γ2, and Γ3 up to fourth order and analyze their dependence on the screened Coulomb interaction integrals U and J. We show that, due to term cancellations, the experimental nearest-neighbor coupling Γ1 is reasonably well reproduced for a whole range of realistic (U,J) values. We show that increasing the Hund's rule coupling J (within the window of realistic values) can lead to large fourth-order contributions, which could explain the ferromagnetic next-nearest-neighbor coupling Γ2 extracted from the spin-wave dispersion. This regime is characterized by a sizable ring exchange K. For (U,J) values that yield a Mott insulator with a half-filled jeff=1/2 state, however, fourth-order terms remain minor even if the gap is small. For no realistic parameters, we find a sizable next-next-nearest-neighbor coupling Γ3∼|Γ2|. Possible implications are discussed. 000902637 536__ $$0G:(DE-HGF)POF4-5221$$a5221 - Advanced Solid-State Qubits and Qubit Systems (POF4-522)$$cPOF4-522$$fPOF IV$$x0 000902637 588__ $$aDataset connected to CrossRef, Journals: juser.fz-juelich.de 000902637 7001_ $$0P:(DE-Juel1)130881$$aPavarini, Eva$$b1$$eCorresponding author 000902637 773__ $$0PERI:(DE-600)2844160-6$$a10.1103/PhysRevB.104.125116$$gVol. 104, no. 12, p. 125116$$n12$$p125116$$tPhysical review / B$$v104$$x1098-0121$$y2021 000902637 8564_ $$uhttps://juser.fz-juelich.de/record/902637/files/PhysRevB.104.125116.pdf$$yOpenAccess 000902637 909CO $$ooai:juser.fz-juelich.de:902637$$pdnbdelivery$$pdriver$$pVDB$$popen_access$$popenaire 000902637 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)130881$$aForschungszentrum Jülich$$b1$$kFZJ 000902637 9131_ $$0G:(DE-HGF)POF4-522$$1G:(DE-HGF)POF4-520$$2G:(DE-HGF)POF4-500$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$9G:(DE-HGF)POF4-5221$$aDE-HGF$$bKey Technologies$$lNatural, Artificial and Cognitive Information Processing$$vQuantum Computing$$x0 000902637 9141_ $$y2021 000902637 915__ $$0StatID:(DE-HGF)0200$$2StatID$$aDBCoverage$$bSCOPUS$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)0160$$2StatID$$aDBCoverage$$bEssential Science Indicators$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)1230$$2StatID$$aDBCoverage$$bCurrent Contents - Electronics and Telecommunications Collection$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)0600$$2StatID$$aDBCoverage$$bEbsco Academic Search$$d2021-05-04 000902637 915__ $$0LIC:(DE-HGF)APS-112012$$2HGFVOC$$aAmerican Physical Society Transfer of Copyright Agreement 000902637 915__ $$0StatID:(DE-HGF)0100$$2StatID$$aJCR$$bPHYS REV B : 2019$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)0113$$2StatID$$aWoS$$bScience Citation Index Expanded$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)0150$$2StatID$$aDBCoverage$$bWeb of Science Core Collection$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)9900$$2StatID$$aIF < 5$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)0510$$2StatID$$aOpenAccess 000902637 915__ $$0StatID:(DE-HGF)0030$$2StatID$$aPeer Review$$bASC$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)1150$$2StatID$$aDBCoverage$$bCurrent Contents - Physical, Chemical and Earth Sciences$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)0300$$2StatID$$aDBCoverage$$bMedline$$d2021-05-04 000902637 915__ $$0StatID:(DE-HGF)0199$$2StatID$$aDBCoverage$$bClarivate Analytics Master Journal List$$d2021-05-04 000902637 920__ $$lyes 000902637 9201_ $$0I:(DE-Juel1)IAS-3-20090406$$kIAS-3$$lTheoretische Nanoelektronik$$x0 000902637 9801_ $$aFullTexts 000902637 980__ $$ajournal 000902637 980__ $$aVDB 000902637 980__ $$aUNRESTRICTED 000902637 980__ $$aI:(DE-Juel1)IAS-3-20090406 000902637 981__ $$aI:(DE-Juel1)PGI-2-20110106