Unconventional planar Hall effect in exchange-coupled topological insulator–ferromagnetic insulator heterostructures
The Dirac electrons occupying the surface states (SSs) of topological insulators (TIs) have been predicted to exhibit many exciting magnetotransport phenomena. Here we report the experimental observation of an unconventional planar Hall effect (PHE) and a gate-tunable hysteretic planar magnetoresist...
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| Format: | Article |
| Language: | English |
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American Physical Society
2018
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| Online Access: | http://hdl.handle.net/1721.1/117672 https://orcid.org/0000-0002-2480-1211 https://orcid.org/0000-0001-7413-5715 |
| _version_ | 1811080700093267968 |
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| author | Wang, Fei Zhao, Weiwei Chan, Moses H. W. Liu, Chaoxing Rakhmilevich, David Moodera, Jagadeesh Chang, Cui-zu |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Wang, Fei Zhao, Weiwei Chan, Moses H. W. Liu, Chaoxing Rakhmilevich, David Moodera, Jagadeesh Chang, Cui-zu |
| author_sort | Wang, Fei |
| collection | MIT |
| description | The Dirac electrons occupying the surface states (SSs) of topological insulators (TIs) have been predicted to exhibit many exciting magnetotransport phenomena. Here we report the experimental observation of an unconventional planar Hall effect (PHE) and a gate-tunable hysteretic planar magnetoresistance in EuS/TI heterostructures, in which EuS is a ferromagnetic insulator (FMI) with an in-plane magnetization. In such exchange-coupled FMI/TI heterostructures, we find a significant (suppressed) PHE when the in-plane magnetic field is parallel (perpendicular) to the electric current. This behavior differs from previous observations of the PHE in ferromagnets and semiconductors. Furthermore, as the thickness of the 3D TI films is reduced into the 2D limit, in which the Dirac SSs develop a hybridization gap, we find a suppression of the PHE around the charge-neutral point indicating the vital role of Dirac SSs in this phenomenon. To explain our findings, we outline a symmetry argument that excludes linear Hall mechanisms and suggest two possible nonlinear Hall mechanisms that can account for all the essential qualitative features in our observations. |
| first_indexed | 2024-09-23T11:35:23Z |
| format | Article |
| id | mit-1721.1/117672 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T11:35:23Z |
| publishDate | 2018 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1176722022-10-01T04:39:00Z Unconventional planar Hall effect in exchange-coupled topological insulator–ferromagnetic insulator heterostructures Wang, Fei Zhao, Weiwei Chan, Moses H. W. Liu, Chaoxing Rakhmilevich, David Moodera, Jagadeesh Chang, Cui-zu Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Plasma Science and Fusion Center Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology) Rakhmilevich, David Moodera, Jagadeesh Chang, Cui-zu The Dirac electrons occupying the surface states (SSs) of topological insulators (TIs) have been predicted to exhibit many exciting magnetotransport phenomena. Here we report the experimental observation of an unconventional planar Hall effect (PHE) and a gate-tunable hysteretic planar magnetoresistance in EuS/TI heterostructures, in which EuS is a ferromagnetic insulator (FMI) with an in-plane magnetization. In such exchange-coupled FMI/TI heterostructures, we find a significant (suppressed) PHE when the in-plane magnetic field is parallel (perpendicular) to the electric current. This behavior differs from previous observations of the PHE in ferromagnets and semiconductors. Furthermore, as the thickness of the 3D TI films is reduced into the 2D limit, in which the Dirac SSs develop a hybridization gap, we find a suppression of the PHE around the charge-neutral point indicating the vital role of Dirac SSs in this phenomenon. To explain our findings, we outline a symmetry argument that excludes linear Hall mechanisms and suggest two possible nonlinear Hall mechanisms that can account for all the essential qualitative features in our observations. National Science Foundation (U.S.) (Grant DMR-1207469) United States. Office of Naval Research (Grant N00014-13-1-0301) National Science Foundation (U.S.) (STC Center for Integrated Quantum Materials. Grant DMR1231319) Alfred P. Sloan Foundation (Research Fellowship) United States. Army Research Office (Young Investigator Program Award W911NF1810198) 2018-09-07T17:11:29Z 2018-09-07T17:11:29Z 2018-09 2018-08 2018-09-06T18:00:09Z Article http://purl.org/eprint/type/JournalArticle 2469-9950 2469-9969 http://hdl.handle.net/1721.1/117672 Rakhmilevich, David, et al. “Unconventional Planar Hall Effect in Exchange-Coupled Topological Insulator–Ferromagnetic Insulator Heterostructures.” Physical Review B, vol. 98, no. 9, Sept. 2018. © 2018 American Physical Society https://orcid.org/0000-0002-2480-1211 https://orcid.org/0000-0001-7413-5715 en http://dx.doi.org/10.1103/PhysRevB.98.094404 Physical Review B Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Physical Society application/pdf American Physical Society American Physical Society |
| spellingShingle | Wang, Fei Zhao, Weiwei Chan, Moses H. W. Liu, Chaoxing Rakhmilevich, David Moodera, Jagadeesh Chang, Cui-zu Unconventional planar Hall effect in exchange-coupled topological insulator–ferromagnetic insulator heterostructures |
| title | Unconventional planar Hall effect in exchange-coupled topological insulator–ferromagnetic insulator heterostructures |
| title_full | Unconventional planar Hall effect in exchange-coupled topological insulator–ferromagnetic insulator heterostructures |
| title_fullStr | Unconventional planar Hall effect in exchange-coupled topological insulator–ferromagnetic insulator heterostructures |
| title_full_unstemmed | Unconventional planar Hall effect in exchange-coupled topological insulator–ferromagnetic insulator heterostructures |
| title_short | Unconventional planar Hall effect in exchange-coupled topological insulator–ferromagnetic insulator heterostructures |
| title_sort | unconventional planar hall effect in exchange coupled topological insulator ferromagnetic insulator heterostructures |
| url | http://hdl.handle.net/1721.1/117672 https://orcid.org/0000-0002-2480-1211 https://orcid.org/0000-0001-7413-5715 |
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