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[Satoshi Sugimoto](https://orcid.org/0000-0002-7148-2372), [Yukiko K. Takahashi](https://orcid.org/0000-0001-9197-7236), [Shinya Kasai](https://orcid.org/0000-0001-7149-4800)

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This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Satoshi Sugimoto, Yukiko K. Takahashi, Shinya Kasai; Near-room temperature topological Hall effect at spin reorientations in sputtered NdCo5−xCux thin film. Appl. Phys. Lett. 31 October 2022; 121 (18): 182404 and may be found at  https://doi.org/10.1063/5.0128572.[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

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[Near-room temperature topological Hall effect at spin reorientations in sputtered NdCo<sub>5−</sub><sub>  <i>x</i></sub>Cu<sub>  <i>x</i></sub> thin film](https://mdr.nims.go.jp/datasets/1719715f-9e05-4322-be49-a23b42064069)

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Near-room temperature topological Hall effect at spin reorientations in sputtered NdCo5−xCux thin filmViewOnlineExportCitationRESEARCH ARTICLE |  NOVEMBER 03 2022Near-room temperature topological Hall effect at spinreorientations in sputtered NdCo5−xCux thin film Satoshi Sugimoto   ; Yukiko K. Takahashi  ; Shinya Kasai Appl. Phys. Lett. 121, 182404 (2022)https://doi.org/10.1063/5.0128572 CHORUSArticles You May Be Interested InTunability of the spin reorientation transitions with pressure in NdCo5Appl. Phys. Lett. (March 2020)Crystal structure, spin reorientation, and rotating magnetocaloric properties of NdCo5-xSix compoundsJ. Appl. Phys. (June 2019)Spin reorientation in NdCo5 single crystalsAIP Conference Proceedings (May 1976)  17 March 2025 05:28:49https://pubs.aip.org/aip/apl/article/121/18/182404/2834714/Near-room-temperature-topological-Hall-effect-athttps://pubs.aip.org/aip/apl/article/121/18/182404/2834714/Near-room-temperature-topological-Hall-effect-at?pdfCoverIconEvent=citejavascript:;https://orcid.org/0000-0002-7148-2372javascript:;https://orcid.org/0000-0001-9197-7236javascript:;https://orcid.org/0000-0001-7149-4800https://crossmark.crossref.org/dialog/?doi=10.1063/5.0128572&domain=pdf&date_stamp=2022-11-03https://doi.org/10.1063/5.0128572https://pubs.aip.org/aip/apl/article-pdf/doi/10.1063/5.0128572/16487045/182404_1_accepted_manuscript.pdfhttps://pubs.aip.org/aip/apl/article/116/10/102408/38776/Tunability-of-the-spin-reorientation-transitionshttps://pubs.aip.org/aip/jap/article/125/24/243901/1058400/Crystal-structure-spin-reorientation-and-rotatinghttps://pubs.aip.org/aip/acp/article/29/1/616/626982/Spin-reorientation-in-NdCo5-single-crystalshttps://e-11492.adzerk.net/r?e=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_dXRtX3NvdXJjZT1BSVAqV2lsZXkmdXRtX21lZGl1bT1Kb3VybmFscyZ1dG1fY2FtcGFpZ249MjAyNXByb21vTG9ja2luR2VuZXJhbF9fO0t3ISFOMTFlVjJpd3RmcyF2OWhacmxjSWVPeWN4VUIzSmhLMkhWNEthdHFpTGt4X3MxUmJUMi0wQUZQdUhtSDRObFNDSzQwWWNDOUFvYmlWUFhzWUstVDBwNUJnODBScHRMNWN3eTdIJCJ9&s=FBghQGyINwXAyT23Kv5AKS06G7QNear-room temperature topological Hall effectat spin reorientations in sputtered NdCo5�xCuxthin filmCite as: Appl. Phys. Lett. 121, 182404 (2022); doi: 10.1063/5.0128572Submitted: 29 September 2022 . Accepted: 17 October 2022 .Published Online: 3 November 2022Satoshi Sugimoto,a) Yukiko K. Takahashi, and Shinya KasaiAFFILIATIONSResearch Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), 1-2-1 Sengen,Tsukuba 305-0047, Japana)Author to whom correspondence should be addressed: SUGIMOTO.Satoshi@nims.go.jpABSTRACTThe spin reorientation in rare-earth intermetallics involves distinctive magnetic morphologies commencing with spontaneous skyrmiontextures without an external magnetic field. Here, we present the sputtering growth of CaCu5-type NdCo5�xCux thin films on MgO (110)substrates. Our films exhibit two successive spin reorientation transitions between the ab-plane and the c-axis, close to the room temperature,apart from the non-uniaxial behavior below 150K. The corresponding modulations of magnetocrystalline anisotropy at reorientation tem-peratures lead to the large topological Hall effect, which can be maintained up to 250K with a maximum Hall resistivity of 210 nX cm. Theseresults of robust topological signals will provide platforms for realizing room-temperature topological magnetic textures.Published under an exclusive license by AIP Publishing. https://doi.org/10.1063/5.0128572The Berry curvature of topological magnetic textures results inthe distinctive transverse Hall current stemming from the interactionof the magnetic order and intrinsic band structure or scattering.1 Theintrinsic anomalous Hall effect (AHE)2–5 and the topological Halleffect (THE)6,7 are two physical phenomena routed to such topologicalorigins. THE is driven by the pseudo magnetic field emerging in themagnetic domains. It is commonly considered as a benchmark for theexistence of topological and/or nonlinear magnetic textures8,9 such asskyrmions. Magnetic skyrmions are nanometric bubble domains witha unit integer topological charge, anticipated as a generation of highdensity, high speed, and low energy consumption information storageunits.10 Room-temperature, zero magnetic field stabilizing skyrmionsare particularly favorable for applications in future devices, owing totheir reduced complication and energy consumption.11 Nonetheless,ground-state stripe domains in most chiral ferromagnetic materialswith Dzyaloshinskii–Moriya interactions (DMIs)12–15 inhibit the stabi-lization of the skyrmion texture in the absence of a magnetic field and/or extrinsic factors.16–19However, recent results have been reported by Zuo et al. demon-strating direct imaging of spontaneous skyrmion type textures in theabsence of an external field over a wide range of temperatures up to280K in rare-earth NdCo5 alloys.20 These key observations have beenattributed to two successive spin reorientation transitions (SRTs) nearroom temperature, known as (1) the “easy-plane” to “easy-cone” tran-sition at TSR1� 240K and (2) the easy-cone to “easy-axis” transitionat TSR2� 280K.21,22 The associated underlying physical principlehas been primarily developed by Moon et al.23 They have proposedthat the perpendicular magnetic anisotropy (PMA) to the in-plane-magnetic-anisotropy (IMA) transition at SRTs can maintain theperpendicular magnetization under very weak DMI, resulting inthe formation of spontaneous skyrmion textures in the in-plane-magnetization system. Such characteristic SRTs are widely observedfor rare earth-cobalt intermetallics arising from the competing mag-netic anisotropies of the rare earth sublattice and the Co sublattice.Thus, the recent discovery of spontaneous skyrmions in NdCo5 hasmotivated the exploration of various topological spin textures in rare-earth intermetallics.Nevertheless, in spite of the unique characteristics related toSRTs, thin film engineering of NdCo5 intermetallics has remainedscarcely explored thus far. Following the early studies of Sm- orNd-included rare-earth intermetallics,24,25 high-energy sputteringtechniques have been commonly employed for the sole fabrication ofamorphous NdCo5 solids, which generally exhibit strong PMA butweak SRT natures.26,27 Bulk SRT characteristics have been observedfor epitaxial NdCo5 thin films by Seifert et al. using the pulsedlaser deposition (PLD) technique.28,29 However, investigations ofAppl. Phys. Lett. 121, 182404 (2022); doi: 10.1063/5.0128572 121, 182404-1Published under an exclusive license by AIP PublishingApplied Physics Letters ARTICLE scitation.org/journal/apl 17 March 2025 05:28:49https://doi.org/10.1063/5.0128572https://doi.org/10.1063/5.0128572https://www.scitation.org/action/showCitFormats?type=show&doi=10.1063/5.0128572http://crossmark.crossref.org/dialog/?doi=10.1063/5.0128572&domain=pdf&date_stamp=2022-11-03https://orcid.org/0000-0002-7148-2372https://orcid.org/0000-0001-9197-7236https://orcid.org/0000-0001-7149-4800mailto:SUGIMOTO.Satoshi@nims.go.jphttps://doi.org/10.1063/5.0128572https://scitation.org/journal/apltopological magnetic domains and related physics have been barelyreported so far.In this Letter, we present the development of a magnetron sput-tering technique for the fabrication of NdCo5 intermetallics, whichreproduce distinctive SRTs of bulk nature. The presence of a topologi-cal Hall effect (THE) associated with SRTs is demonstrated through-out magneto-transport measurements. Fractional substitutions of Cosites by Cu atoms in CaCu5-type NdCo5 are adopted to improve thecrystallinity of thin film samples, enabling robust THEmaintained at awide temperature range. We further observe non-uniaxial magneto-crystalline anisotropy (MCA) at lower temperature, where additionalHall signals phenomenologically increase due to the shape effect ofthin films.NdCo5�xCux thin films (10–50nm) were grown on MgO (110)substrates with a 10nm thick Cr buffer layer using dc magnetron co-sputtering from Nd, Co, and Cu targets. The MgO substrates wereannealed at 600 �C for 1 h, and a Cr buffer was sputtered on the sur-face at 400 �C. Subsequently, NdCo5�xCux films were sputtered at600–800 �C prior to adding a capping layer of 5 nm thick Ta.Stoichiometry of the resulting NdCo5�xCux films was evaluated asx¼ 0.0, 0.6, 1.3, and 2.0 using x-ray fluorescence analysis (XRF,Rigaku). The crystal structures of the NdCo5�xCux films were charac-terized using x-ray diffraction (XRD, Rigaku) with a Cu-Ka source(k¼ 1.5406 Å). Magnetization measurements were performed by avibrating sample magnetometry technique using a magnetic propertymeasurement system (MPMS, Quantum Design). The transport prop-erties were measured for the 20–40lm width Hall bars by a four-probe method using a physical property measurement system (PPMS,Quantum Design).The NdCo5 hexagonal crystal forms a CaCu5-type structure, classi-fied in the space group P6/mmm, no. 191. The XRD profiles ofNdCo5�xCux films shown in Fig. 1(a) confirm the formation of an Nd-Cophase with an orientation of the c-axis parallel to the MgO (001) directionin agreement with former studies of PLD deposited NdCo5 systems.28Sharpe NdCo5 (1010) and (2020) peaks are observed at 2h positions of20.8� and 42.7� for Cu-free NdCo5 sputtered films onto the crystallized Crbuffer layer along the (211) orientation. The texture relation is summa-rized as NdCo5 1010ð Þ½0001� k Crð211Þ½011� k MgOð110Þ½001�.By increasing the Cu content in the NdCo5�xCux films fromx¼ 0.0 to x¼ 2.0, a decrease in the width of the (1010) and (2020)peaks is observed, accompanied by the emergence of the (3030) and(4040) higher peaks at 2h ¼ 63.7� and 89.5�. This reveals a notableimprovement in the crystallinity of sputtered films by substituting Cosites with small amounts of Cu. The FWHM of a rocking curve of x-scans at (2020) peaks for different Cu contents is plotted in Fig. 1(b).The width decreases linearly with increasing Cu content for lowertemperature sputtering at 600 �C. For higher temperature sputtering at800 �C, the FWHM notably decreases from x¼ 0.0 to x¼ 0.4, and itreaches to Dx < 1� for higher Cu contents. Such distinctive improve-ment of the sputtered films can be attributed to the high solubility ofCu atoms in the CaCu5-type crystal, which has been discovered ear-lier.30 Note that Cu substitutions also affect MCA assigned to adecrease in the net magnetic moment at each Cu site. The c-axis MCAconstant K for lower temperature sputtering is plotted in Fig. 1(b).MCA shows a monotonic decrease with increasing Cu contents,indicating higher Cu substitution will degrade the original magneticproperties of the CaCu5-type NdCo5 crystal. For balancing the highcrystallinity and large MCA, we would focus on NdCo4.4Cu0.6(x¼ 0.6) samples for subsequent discussions.The temperature dependencies of the magnetization process forNdCo4.4Cu0.6 thin films are presented in Fig. 2(a). The zero-field cool-ing process exhibits an abrupt decrease in the magnetization along thec-axis around T¼ 275K, reflecting to the easy-axis to easy-cone transi-tion labeled as TSR2. The magnetization is completely diminishedaround T¼ 230K, which corresponds to the rotation of the easy axisto the ab-plane, referred to as the easy-cone to easy-plane transition atTSR1. These successive reorientation processes are also observed at thesame temperatures for the zero-field heating process. This indicatesthat SRTs, unique to CaCu5-type NdCo5, are plausibly reproduced forour sputtered thin films. It is worth noting that these SRTs, observedin our texture relation, correspond to the PMA to IMA transitionapplicable for spontaneous skyrmions formations.20,23Further details regarding the magnetization process related toSRTs can be discussed from the hysteresis loops along the threeFIG. 1. Structural characterization of the NdCo5�xCux sputtered thin films. (a) X-raydiffraction patterns of a 25 nm NdCo5�xCux thin film. Different Cu contents withx¼ 0, 0.6, and 1.3 are plotted with black, red, and green colors, respectively. Thetexture relation with the MgO substrate is depicted in the inset. (b) The full width athalf maximum of the NdCo5 (2020) peak (black open and closed symbols) and thec-axis magnetocrystalline anisotropy constant K (red symbols) for different Cu con-tents. Values of K are investigated for 600 �C annealed films at 400 �C.Applied Physics Letters ARTICLE scitation.org/journal/aplAppl. Phys. Lett. 121, 182404 (2022); doi: 10.1063/5.0128572 121, 182404-2Published under an exclusive license by AIP Publishing 17 March 2025 05:28:49https://scitation.org/journal/aplcrystalline orientations shown in Fig. 2(b). For the easy-axis phase at300K, the square-shaped hysteresis loop is obtained only along theMgO (001) direction. Meanwhile, the hard-axis behaviors are observedalong the MgO (110) and (110) directions, indicating that the uniaxialMCA axis is along the c-axis. At 250K, the square hysteresis is oncediminished, and soft magnetization loops along the MgO (001) and(110) directions are obtained. These results reproduce the easy-conephase, where the MCA axis is intermediately tilted from the c-axisdirection toward the ab-plane. Note that only the magnetizationprocess along the MgO (110) direction shows the strong hard-axisbehavior due to the large demagnetization field characteristic ofnanometer-scale thickness films. For the easy-plane phase at 200K,the easy-axis hysteresis is obtained along the MgO (110) direction,showing a rotation of the MCA axis from the c-axis direction to theab-plane. These three distinctive MCA rotations are inherited inCaCu5-type NdCo5.Meanwhile, the unique hysteretic behaviors start to appear oncethe temperature decreases below 150K. At 125K, the magnetizationprocesses along both MgO (110) and (110) directions exhibit step-likehysteretic behaviors. These results can be regarded as the “biaxial ab-plane” MCA rather than a simple “uniaxial” MCA rotation unique toCaCu5-type NdCo5. Such a complex MCA is considered in associationwith the enhanced PMA component at low temperatures and/oreffects of the mixed crystal with the Nd-rich solids as discussed inFig. 4. Stabilizations of multi-domains and/or nonlinear magnetic tex-tures within the ab-plane are conceivable from the hysteresis shapes atthis temperature range. The sign of this additional “biaxial” phase isalso observed as a small kink at T� 150K at the zero-field heatingcurve, labeled as TSR10 where magnetization exhibits a slight increasefrom the easy-plane phase. These three distinctive SRTs also affect lon-gitudinal and transport properties in Figs. 3(a) and 3(b). The two tinykinks appear around 260 and 160K. The former allocates betweenTSR2 and TSR1, and the latter lies in the vicinity of TSR10 correspondingto SRT temperatures in Fig. 2(a).Magneto-transport properties in NdCo4.4Cu0.6 sputtered filmsare discussed by measuring the Hall resistivity at each reorientationphase. The total Hall resistivity qxy can be described from contribu-tions of the ordinary Hall effect (OHE), AHE, and THE, asqxy ¼ qOHExy þ qAHExy þ qTHExy . The resistivity of OHE is linearly propor-tional to the external field H, described as qOHExy ¼ R0H, with a Hallcoefficient R0. The modern understanding of AHE includes intrinsicand side-jump scattering contributions.1,31 Thus, the resistivity couldbe expressed as qAHExy � SAq2xxM using a scaling coefficient SA, longi-tudinal resistivity qxx , and the magnetization M. The remaining resis-tivity of THE can be simplified as follows:qTHExy ¼ qxy � R0H � SAq2xxM:Figure 4 exhibits the field dependencies of qxy , qOHExy þ qAHExy , andqTHExy for a 25 nm thick NdCo4.4Cu0.6 sample at different reorientationphases, as the easy-axis (T¼ 300K), easy-cone (250K), easy-plane(200K), and biaxial ab-plane phases below TSR10 (125 K). The valuesof R0 and RS are estimated at the uniformly saturated condition underH¼ 4 T. When the NdCo4.4Cu0.6 film shows an easy-axis MCA at300K, the difference between qxyðHÞ and qOHExy ðHÞ þ qAHExy ðHÞ curveis almost negligible. This indicates the negligible topological contribu-tion onto magnetization here. Once the temperature decreases belowTSR2 to 250K, the NdCo4.4Cu0.6 film shifts to an easy-cone phase, asconfirmed in Fig. 2(a), and the PMA to IMA transition affects theunderlying magnetic textures. As expected, the qxyðHÞ curve shows aclear difference from qOHExy ðHÞ þ qAHExy ðHÞ at zero-field vicinityHj j < 1T, and an apparent nonzero topological contribution isdetected. qTHExy shows a symmetric behavior against zero field and ismaximized at H¼60.3T up to qTHExy jmax �88 nX cm. The obtainedtopological signal scale and its external field evolution show a goodFIG. 2. Magnetic property of 25 nm thick NdCo4.4Cu0.6 films. (a) Temperaturedependencies of the magnetic moment M for the zero-field cooling (black) and thezero-field heating (red) processes. The sample magnetization is once saturated byan external 6 T field along the MgO (001) (cooling) or (110) (heating) directions. (b)Hysteresis loops along the MgO (001) (black), ð110) (red), and (110) (green) direc-tions for the easy-axis phase (T¼ 300 K, top), easy-cone phase (250 K, second),easy-plane phase (200 K, third), and biaxial ab-plane phase (125 K, bottom).Schematics of the MCA axis at each phase are depicted in the insets.Applied Physics Letters ARTICLE scitation.org/journal/aplAppl. Phys. Lett. 121, 182404 (2022); doi: 10.1063/5.0128572 121, 182404-3Published under an exclusive license by AIP Publishing 17 March 2025 05:28:49https://scitation.org/journal/aplconsistency with direct imaging results by TEM observations reportedin Ref. 20. According to this report, the spontaneous enclosed in-planedomains (EIPDs) and stripe domains are stabilized as magnetic groundstates in the absence of an external field. These domains transform intobiskyrmions32 under a small field range of 0.2–0.3T, leading to a finiteTHE. Under a higher external field, such biskyrmions are swept away,resulting in a “hump-like” shape in the THE field dependenciesobserved in Fig. 4. The emergence of such a distinctive topological Hallsignal is also observed for the easy-plane phase at 200K, where the max-imum signal amplitude and the peak field positions remain almost con-stant from the easy-cone phase at 250K. These results imply that EIPDsand/or biskyrmions are stabilized in the wide temperature range fromeasy-cone to easy-plane phases (150K<T� 250K).At a further low temperature (125K), the biaxial MCA behaviorresults in an increment of the topological contribution up to qTHExy jmax�162 nX cm at the peak positions of H¼60.5T. In addition,qTHExy curves indicate small hysteretic behaviors between the differentfield sweep directions. These lower temperature characteristics areunique to thin film samples, implying a stabilization of other types ofnonlinear magnetic textures. As is apparent in results of 125K in Fig.2(b), thin film samples exhibit a finite PMA component involved forstabilizing conventional PMA skyrmions33,34 and/or magnetic vorti-ces.35 PMA skyrmions and/or vortices possess constant topologicalcharges at zero-field vicinity, resulting in unique two-block shapes intheir hysteresis loops.35–37 The quenched-shaped magnetization curveat 125K (approximated by qOHExy þ qAHExy ) in Fig. 4 shows certain analo-gies with a feature of such two-block shape hysteresis loops, inferringstabilization of these chiral magnetic textures. On the other hand, it isdifficult to exclude multicarrier effects attributed to the non-CaCu5-typeNd intermetallics. Nd-rich Ce2Ni7-type Nd2Co7 shows good latticematches with CaCu5-type NdCo5 in hexagonal lattice constanta¼ b¼ 5.02 Å with c¼ 4.06 Å (NdCo5) and c¼ 24.36 Å (Nd2Co7)28,38FIG. 4. Hall resistivities of 25 nm NdCo4.4Cu0.6 films under the out-of-plane mag-netic field for the easy-axis (T¼ 300 K, top panel), easy-cone (250 K, second),easy-plane (200 K, third), and biaxial ab-plane phases (125 K, bottom). Total resis-tivities qxy , the sum of ordinary and anomalous Hall resistivities qOHExy þ qAHExy , andtopological Hall resistivities qTHExy are plotted by black, red, and green symbols,respectively.FIG. 3. Temperature dependence of the (a) longitudinal resistivity qxx and (b) trans-verse resistivity qxy of 25 nm thick NdCo4.4Cu0.6 films. The spin reorientation tem-peratures TSR10, TSR1, and TSR2 obtained from Fig. 2 are marked by closed or opentriangles.Applied Physics Letters ARTICLE scitation.org/journal/aplAppl. Phys. Lett. 121, 182404 (2022); doi: 10.1063/5.0128572 121, 182404-4Published under an exclusive license by AIP Publishing 17 March 2025 05:28:49https://scitation.org/journal/apland difficult to be identified from XRD measurements in Fig. 1(a). Thephase mixture with Nd-rich crystals might affect low temperature trans-ports there.The temperature evolution of THE, measured every 25K, isshown as the contour maps of qTHExy in Fig. 5. The results of positivefield sweep directions from �4 to þ4T and from þ4 to �4T areshown in Figs. 5(a) and 5(b), respectively. A finite THE starts toappear when NdCo4.4Cu0.6 shows the easy-cone phase below TSR2. Atthis temperature range, qTHExy increases by decreasing temperature andtakes the local maximum around the easy-plane phase at TSR1. In therange of TSR10 < T< TSR1, the amplitude of THE remains almost con-stant as qTHExy �100 nX cm with negligible difference between two dif-ferent field sweep directions. Moreover, the peak positions of qTHExy ðHÞremain consistent as jHj ¼ 0.3–0.4T by implying the EIPD to biskyr-mion transitions at zero field vicinity, as observed in the direct imagingresults in Ref. 20. These behaviors are distinctively changed at the biax-ial ab-plane phase below TSR10. The clear differences observed betweenfield sweep directions indicate that the remanent THE after fieldswitching [i.e., H> 0 in Fig. 5(a) or H< 0 in Fig. 5(b)] is notablylarger. Further studies of micromagnetic and microstructure analyseswill be required to discuss the details of THE origins at this tempera-ture range.In summary, we explored the magnetron sputtering fabricationof the CaCu5-type NdCo5�xCux thin films and observed a large THEat successive spin reorientations from the easy-plane, easy-cone, toeasy-axis transitions. The obtained THE at 150K<T� 250K showsgood consistency with the results of the early report on bulk NdCo5,indicating stabilization of spontaneous EIPD and/or skyrmion texturesat zero field vicinity. The additional biaxial ab-plane MCA behaviorappears below 150K, associated with the nontrivial magnetic texturesand transport properties at the lower temperature range. These obser-vations of near-room temperature topological signals in thin filmswith the low-cost fabrication process will be an incremental steptoward further development of spintronic devices using rare-earthintermetallics.This work was partially supported by the Japan Society for thePromotion of Science (JSPS) KAKENHI via Grant Nos.JP20K14419 and JST, PRESTO via Grant No. JPMJPR18L3, Japan.AUTHOR DECLARATIONSConflict of InterestThe authors have no conflicts to disclose.Author ContributionsSatoshi Sugimoto conceived the project, planned and performedexperiments, and analyzed data. Satoshi Sugimoto, Y. K. Takahashi,and Shinya Kasai wrote the main text.Satoshi Sugimoto: Conceptualization (lead); Data curation (lead);Formal analysis (lead); Funding acquisition (equal); Investigation(lead); Methodology (lead); Project administration (lead); Writing –original draft (lead); Writing – review & editing (lead). Y. K.Takahashi: Funding acquisition (equal); Project administration(equal); Writing – review & editing (equal). Shinya Kasai: Fundingacquisition (equal); Project administration (equal); Resources (equal);Supervision (equal); Writing – review & editing (equal).DATA AVAILABILITYThe data that support the findings of this study are availablefrom the corresponding author upon reasonable request.REFERENCES1N. Nagaosa, J. Sinova, S. Onoda, A. H. MacDonald, and N. P. Ong, Rev. Mod.Phys. 82, 1539 (2010).2R. Karplus and J. M. Luttinger, Phys. Rev. 95, 1154 (1954).3J. Smit, Physica 24, 39 (1958).4L. Berger, Phys. Rev. B 2, 4559 (1970).5Z. Fang, N. Nagaosa, K. S. Takahashi, A. Asamitsu, R. Mathieu, T.Ogasawara, H. Yamada, M. Kawasaki, Y. Tokura, and K. Terakura, Science302, 92 (2003).6J. Ye, Y. B. Kim, A. J. Millis, B. I. Shraiman, P. Majumdar, and Z. Te�sanovic,Phys. Rev. Lett. 83, 3737 (1999).7P. Bruno, V. K. Dugaev, and M. Taillefumier, Phys. Rev. Lett. 93, 096806(2004).8W. Wang, Y. Zhang, G. 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