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describethephysicsofthree-flavorfermionicatomsinopticallattices. Anumberofsurprisingresults, suchasthethree-sublatticeorderedpatternonabipartitelatticeandthedifferentroleplayedbyquantum andthermalfluctuationswereobtained. Enhancedsymmetriesinthecoldatomicgaseswerealsothe maintopicoftheeffectivefield-theoreticalstudyin[6],wherethepresenceofmultipolarstateswas establishedforspin-3/2fermionsnearthehalf-filling. Theoreticalmodelsforfrustratedmagneticmaterials. Thefrustratedpyrochlorematerial Er2Ti2O7 exhibitsauniquenonplanarmagneticstructure. Basedonthenatureofthelowest-energycrystal-field levelswederiveaneffectivetheoreticalmodelfor Er2Ti2O7:aquantumspin-1/2 XYantiferromagneton apyrochlorelattice[7].Theanalyticalcalculationsforthismodelshowthatzero-pointfluctuationsselect theexperimentallyobservedmagneticstructureoutofinfinitelydegeneratemanifoldofclassicalground states.Theoreticalsupportwasalsoprovidedfortheultrasonicexperimentsonthespinelantiferromagnet CdCr2O4inhighmagneticfields[8]. Thefractionalmagnetizationplateauandnewhigh-fieldphasesinthetriangularantiferromagnet Cs2CuBr4 providefurtherinterestingexampleoftheorderfromdisorderphenomenoninmagnetism.Theoreticaldescriptionofthismaterialrequiresextensionofthepreviousresultstothecaseofthespatiallyanisotropic lattice.Theanisotropictriangularantiferromagnetwastheoreticallystudiedusingsymmetryanalysisand thesemiclassicallarge-Sexpansionnearthesaturationfield Hsandcloseto 1 3 Hs[9]. Thenontrivial behaviorwasfoundforarangeofparametersincludingpresenceofaclassicallyunstableincommensurateplanar“fan”state,anon-coplanardouble-spiralphase,andtwonon-coplanarconephaseswithand withoutbroken Z3symmetry. OneadditionalresearchtopicinthisdirectionwastheinvestigationoftheeffectoftheDzyaloshinskii- Moriya(DM)interactioninstronglyfrustratedmagnets. AlthoughtheDMtermisnominallyweak,at mostafewpercentofthedominantexchangeinteraction,itsrolecanbesignificantinfrustratedmagnets, wherethegroundstateishighlydegenerateattheclassicallevelandwherethereisahighdensityof low-energy,excitationsclosetocondensation. TheeffectoftheDMinteractionwasstudiedforthe spin-1/2kagomeantiferromagnet[10],realizedinherbertsmithite,andfortheorthogonaldimermaterial SrCu2(BO3)2[11]. ThejointprojectwiththeESRgroupatHMDwasdevotedtotheinvestigation ofmagneticexcitationsincopperpyrimidinedinitrate,aspin-1/2antiferromagneticchainwithboth alternating g-tensorandtheDMinteractions. Atransitionfromthesine-Gordonregion(withsolitonbreatherelementaryexcitations)toaspin-polarizedstate(withmagnonexcitations)wasidentifiedat Hs ≈ 48.5T.Thisinterpretationisfurtherconfirmedbythequantitativeagreementwiththenumerical DMRGresultsforaspin-1/2Heisenbergchainwithastaggeredtransversefield,overtheentirefield rangeoftheexperimentaldata. Unconventionalspindynamicsinhighfields. Surprisinglyenough,thedynamicalpropertiesofall quantumantiferromagnetsundergoratherdramatictransformationinstrongmagneticfieldsevenatzero temperature. Thisisrelatedtothefield-inducedspontaneousmagnondecays,whicharedetermined bycubicanharmonicitiesintheeffectivebosonHamiltonian. Thereisadeepanalogybetweencubic nonlinearitiesinthemagnonHamiltonianofanoncollinearantiferromagnetandthepresenceofsimilar interactiontermsinasuperfluidbosonsystems.Aninterestingaspectofthedynamicsintwo-dimensional quantumspinsystemsisthedecayenhancementduetoVanHovesingularitiesinthetwo-particledensity ofstates.Aself-consistentregularizationschemewasdevelopedforamodelexampleofthesquare-lattice Heisenbergantiferromagnet,whichexhibitsdecaydynamicsinthevicinityofthesaturationfield[13]. Generalaspectsofmagnon-magnonandmagnon-phononinteractionsonthethermaltransport,including theroleofspontaneousdecays,weretreatedin[14]. [1] M.E.ZhitomirskyandH.Tsunetsugu,Europhys.Lett.92(2010)37001. [2] L.JaubertandP.C.W.Holdsworth,J.Phys.Condens.Matter23(2011)164222. [3] S.R.Giblin,S.T.Bramwell,P.C.W.Holdsworth,D.Prabhakaran,andI.Terry,NaturePhysics7(2011)252. [4] N.Moloney,L.JaubertandP.C.W.Holdsworth,inpreparation(2011). [5] T.A.Toth,A.M.Laeuchli,F.Mila,andK.Penc,Phys.Rev.Lett.105(2010)265301. [6] A.KolezhukandT.Vekua,Phys.Rev.B83(2011)014418. [7] Z.Hao,M.E.Zhitomirsky,P.C.W.Holdsworth,andR.Moessner,inpreparation(2011). [8] S.Bhattacharjee,S.Zherlitsyn,O.Chiatti,A.Sytcheva,J.Wosnitza,R.Moessner,M.E.Zhitomirsky,P.Lemmens,V.Tsurkan, A.Loidl, arXiv:1011.4076,tobepublishedinPhys.Rev.B(2011). [9] O.StarykhandA.Chubukov,inpreparation(2011). [10] O.Tchernyshyov,I.Rousochatzakis,andF.Mila,inpreparation(2011). [11] J.Romhanyi,K.Totsuka,andK.Penc,Phys.Rev.B83(2011)024413. [12] S.A.Zvyagin,E.Cizmar,M.Ozerov,J.Wosnitza,R.Feyerherm,S.R.Manmana,F.Mila,Phys.Rev.B83(2011)060409. [13] M.Mourigal,M.E.Zhitomirsky,andA.L.Chernyshev,Phys.Rev.B82(2010)144402. [14] S.Gangadharaiah,A.L.Chernyshev,andW.Brenig,Phys.Rev.B82(2010)134421. 36 ScientificWorkanditsOrganizationatthe<strong>Institut</strong>e–anOverview
AdvancedStudyGroup2010:Quantumthermodynamicsoffinitesystems (Convenor:Prof.Dr.GerhardC.Hegerfeldt) Members: J.GonzaloMuga(UniversidaddelPasVasco,Spain),LarrySchulman(ClarksonUniversity, USA),BernardGaveau(UniversitParisVI,France),GiulioCasati(UniversitdegliStudidell’Insubria, Italia),RafaelSala-Mayato(UniversidaddeLaLaguna,Spain) TheAdvancedStudyGrouptookplacefromJunetoSeptember2010. Thecompositionofthegroup changedwithtimeandasaconsequencetheresearchpersuedandtheemphasisputondifferentresearch topicsalsochangedwithtime. FromthestartoftheASG,Gaveau,Schulmanandtheconvenorwerepresent.Thetwoformercontinued towrestlewiththeirthermodynamicsresearchonpower,smallenginesandentanglement. Interpreting the“study”mandatebroadly,therewasanintenseinteractionforaweekwithavisitorfromAthens, AntigoneNounou,aphilosopherwithphysicsbackgroundandinterestsingaugefieldsandtheAharonov- Bohmeffect. AntigoneNounouisoneofthoseparticipatinginacurrentdebateinthephilosophy communityontherealityofgaugefields.Duringhervisittothe mpipksshegavearousingseminaron “explanation”,“rousing”inthesensethatsomeofthosewhoattendedwererousedfromskepticismand self-assurance,torealizethatitcansometimesbedifficulttoknowwhatwemeanasexplanation.The realitydebatecanlikewisebedifficultforthephysicisttoappreciate,butinanycasethequestionshe raisedchallengedSchulman’snotionofhowtodealwithmultipleconnectnessinthepathintegral.The outcomewasapreprint,co-authoredbyGaveau,NounouandSchulman,inwhichtheoriginalhomotopy ideasretaintheirvalidityinthecontextofthetime-dependentAharonov-Bohmeffect. Therewasalso overlapwiththeconvenor’srecentexplanationoftheAharonov-Bohmeffectthroughforces. Whiletheadvancedstudygroupwasinsessionquiteanumberofworkshopsandconferenceswereheld atthe mpipks,andofcoursetheparticipantsoftheASGtooktheopportunitytoattendsomeofthe lectures.InaworkshoponBECatthe mpipkstherewasatalkbyJ.Schmiedmayer(Vienna)reporting experimentalworkrelatingtothermalizationforatomsintraps.Thiswasofobviousinterestforus,and duringdiscussionswithhimhesuggestedinvitingI.MazetsfromhisgroupasavisitortotheASG.The latter’svisitledtoanintenseinterchangeonthermalizationinquantumoptics. Asregardsthenumberofmembersandvisitorspresent,Augustwasthebusiestmonth. Themembers GonzaloMuga,LarrySchulman,BernardGaveau,RafaelSala-Mayatoandtheconvenorwerejoined towardtheendofAugustbyGiulioCasati.ThevisitorsinAugustincludedYairEzer,ErikKosloff,Erik Torrontegui,DavidGuery-Odelin,AndreasRuschhaupt,DanielAlonso,andGünterMahlerwhovisited forthreeweeks. ThecollaborationofA.RuschhauptandG.MugawithG.Mahler,withhisexpertise,clarifiedathermodynamicaldescriptionofone-waybarriersandatomdiodes.TheoverlapwithCasatisgroupwasalso stimulating,astheyproposeheat-one-waybarriers.Thesearemostlyclassicaldevices,andthechallenge wastofindaquantumphysicalimplementation. DuringaninformaltalkbyR.Sala-MayatoontheproblemshewasinvestigatingwithG.Mugathe convenorremarkedonaconnectiontothemeasuringproblemasformulatedbyvonNeumannandlater somewhatdifferentlybyLüders. Outofthisremarkhasgrownacollaborationonhowtopossibly distinguishexperimentallybetweenthesetwoapproaches. InthelastmonthoftheASG,thethermoelectriceffectandtheassociatedthermodynamicefficiency, writtenintermsoftheso-calledfigureofmerit ZT,wasexaminedingreatdetailinjointdiscussionsby CasatiandparticipantsoftheASG.Inparticulartheincreaseof ZTwasinvestigated.Theunderstanding ofthepossiblemicroscopicmechanismleadingtoanincreaseof ZT isatpresentquitelimited. These commonsessionstookplaceeverydayandlastedseveralhourseachday. Themainpointisthat dynamicalnonlinearsystemsmayprovideanewapproachtotheproblemandmayallowtounveilthe physicalmechanismswhichmayleadtohighthermoelectricefficiency. Asaresultofthesediscussions severallinesoffutureresearchhavebeenproposed,discussedanddetermined.Researchalongtheselines isnowinprogressasacollaborationamongdifferentscientistswhohaveparticipatedinthestudygroup. ParticipantsoftheASGestablishedfruitfulinteractionswithotherresearchersofthe mpipksandwith membersoftheTechnicalUniversityofDresden,inparticularwithMasudulHaque,IngridRotterand MarkMineev-Weinsteinfromthe mpipksaswellaswithAlexanderEisfeldandRolandKetzmerickfrom theuniversity. 1.10. AdvancedStudyGroups 37
Page 1 and 2: Contents 1 ScientificWorkanditsOrga
Page 3 and 4: Chapter1 ScientificWorkanditsOrgani
Page 5 and 6: 2009-2010 •In2009Dr.K.Hornbergera
Page 7 and 8: possibilityforyoungscientiststotake
Page 9 and 10: manipulationofchargequbits.TakingCo
Page 11 and 12: Matter wave interference with compl
Page 13 and 14: interactinggas,futureworkwilladdres
Page 15 and 16: scalesrangingfromindividualhaircell
Page 17 and 18: Ohio(Neiman). Problemsfromcellbioph
Page 19 and 20: oleofdisorderinexoticstronglycorrel
Page 21 and 22: architectures.Togetherwithdeveloper
Page 23 and 24: September.Theverysamefoundationsupp
Page 25 and 26: many-bodyeffectsinquantumdots. Even
Page 27 and 28: insystemsexhibitingalong-rangeinter
Page 29 and 30: experimentalprobesleadtoperturbatio
Page 31 and 32: andefficiency. Theyarethereforewell
Page 33 and 34: isdefinedbyaslow-downofcelldivision
Page 35: 1.10 AdvancedStudyGroups AdvancedSt
Page 39: InJanuaryattentionturnedtocoldatoms
Page 42 and 43: 2.1 Photo Activated Coulomb Complex
Page 44 and 45: 2.2 Molecular bond by internal quan
Page 46 and 47: 2.3 Modular Entanglement in Continu
Page 48 and 49: 2.4 Rotons and Supersolids in Rydbe
Page 50 and 51: 2.5 Electromagnetically Induced Tra
Page 52 and 53: 2.6 Delayed Coupling Theory of Vert
Page 54 and 55: 2.7 Reorientation of Large-Scale Po
Page 56 and 57: 2.8 Coupling Virtual and Real Hair
Page 58 and 59: 2.9 How Stochastic Adaptation Curre
Page 60 and 61: 2.10 Experimental Manifestations of
Page 62 and 63: 2.11 The Statistical Mechanics of Q
Page 64 and 65: 2.12 Entanglement Analysis of Fract
Page 66 and 67: 2.13 Quantum Spin Liquids in the Vi
Page 68 and 69: 2.14 Work Dissipation Along a Non Q
Page 70 and 71: 2.15 Probabilistic Forecasting JOCH
Page 72 and 73: 2.16 Magnetically Driven Supercondu
Page 74 and 75: 2.17 Quantum Criticality out of Equ
Page 76 and 77: 2.18 High-Quality Ion Beams from Na
Page 78 and 79: 2.19 Terahertz Generation by Ionizi
Page 80 and 81: 2.20 Many-body effects in mesoscopi
Page 82 and 83: Bone is a complex tissue that is be
Page 84 and 85: Cooperation is a central phenomenon
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2.23 Measuring the Complete Force F
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2.24 Pattern Formation in Active Fl
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2.25 Magnon Pairing in a Quantum Sp
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2.26 Shortcuts to Adiabaticity in Q
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2.27 Itinerant Magnetism in Iron Ba
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2.28 Kinetochores are Captured by M
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Chapter3 DetailsandData 3.1 PhDProg
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IMPRSmeetinginBadSchandau(Sächsich
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thephysicsofcomplexsystems.In2009we
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|| 2 1 0.8 0.6 0.4 0.2 0 2 4 6 8 10
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• C.F.Lee,L.Jean,C.Lee,M.Shaw,and
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Externalcollaborations WithA.Chubuk
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continuousspectrum)attheedgeoftheKA
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• Non-centrosymmetricsuperconduct
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20. TCS-PROGRAM:SynchronizationandM
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3.3.7 WorkshopParticipationandDisse
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participatedwhichopenedaparticularw
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Longhi,Malpuech,Peschel,Ruo)andphot
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inferencecanbeused.Thesetopicswerea
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Scientificresults: Thestatementthat
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Altogether,wereceivedverypositivefe
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oftherapidlymaturingtheoryoffixedde
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modeling(HansBraun,DmitryPostnov),a
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moreexperiencedresearchesasthesewer
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Forthismeeting,wedecidedtochoosetwo
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Summary. Theworkshopcollectedandatt
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mpipks colloquium given by S. Ospel
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approachestononlinearquantumopticsw
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climatedata.Finally,PeterTalknerdem
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(e.g. Carl-PhilipHeisenberg,Charlot
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3.4.3 AdditionalExternalFunding •
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3.5.2 Degrees Habilitations • Lin
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3.6 PublicRelations 3.6.1 LongNight
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3.7 BudgetoftheInstitute Thefollowi
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52% 56% 13% 11% Budgetforpersonnel
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In 2010 a large parallel cluster wa
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Gugliandolo,L. ProfessorDr. Laborat
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Orosz,H. Oberbürgermeisterinder La
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Chapter4 Publications 4.1 Light-Mat
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Taya,S.A.,M.M.ShabatandH.M.Khalil:
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Oh,S.: Geometricphasesandentangleme
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Stoyanova,A.,L.Hozoi,P.FuldeandH.St
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Thielemann,B.,C.Rüegg,H.M.Rønnow,
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2010 Charrier,D.andF.Alet:Phasediag
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Gvozdikov, V.M.: Compositefermionsw
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Lindner,B.,D.Gangloff,A.LongtinandJ
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Denisov,S.I.,W.HorsthemkeandP.Häng
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Gogberashvili, M.andR.Khomeriki: Tr
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Wang,Q.J.,C.Yan,L.Diehl,M.Hentschel
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Contents - Max-Planck-Institut für Physik komplexer Systeme

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