Positive Oscillating Magnetoresistance in a van der Waals Antiferromagnetic Semiconductor

Article Article scientifique Article Positive Oscillating Magnetoresistance in a van der Waals Antiferromagnetic Semiconductor eng 2025-01-30 author Lin Xiaohanwen 0000-0002-4144-5466 Université de Genève 974954 Département de physique de la matière quantique (FIMAC) author Wu Fan 0000-0002-7967-6518 Université de Genève author Ubrig Nicolas 0000-0002-1966-4435 Université de Genève 742176 author Liao Menghan 0000-0001-9108-3013 Université de Genève 969080 author Yao Fengrui 0000-0003-3754-0628 Université de Genève 944537 Département de physique de la matière quantique (FIMAC) author Gutierrez Lezama Ignacio 0000-0003-1280-915X Université de Genève 681297 Département de physique de la matière quantique (FIMAC) author Morpurgo Alberto 0000-0003-0974-3620 Université de Genève 666794 Département de physique de la matière quantique (FIMAC) 011017 10.1103/PhysRevX.15.011017 2160-3308 https://link.aps.org/doi/10.1103/PhysRevX.15.011017 In all van der Waals layered antiferromagnetic semiconductors investigated so far, a negative magnetoresistance has been observed in vertical transport measurements, with characteristic trends that do not depend on applied bias. Here, we report vertical transport measurements on a layered antiferromagnetic semiconductor CrPS 4 that exhibit a drastically different behavior, namely, a strongly bias-dependent, positive magnetoresistance that is accompanied by pronounced oscillations for devices whose thickness is smaller than 10 nm. We establish that this unexpected behavior originates from transport being space-charge limited and not injection limited as for the layered antiferromagnetic semiconductors studied earlier. Our analysis indicates that the positive magnetoresistance and the oscillations only occur when electrons are injected into in-gap defect states, whereas when electrons are injected into the conduction band, the magnetoresistance vanishes. We propose a microscopic explanation for the observed phenomena that combines concepts typical of transport through disordered semiconductors with known properties of the CrPS 4 magnetic state, thus capturing all basic experimental observations. Our results illustrate the need to understand, in detail, the nature of transport through vdW magnets in order to extract information about the nature of the order magnetic states and its microscopic properties. Dewey 500.2 Swiss National Science Foundation 2D Magnetic Materials 219424 CH Projects 33 Département de physique de la matière quantique 131 35 Groupe de physique appliquée 135 false 678 Groupe Morpurgo https://doi.org/10.26037/yareta:rxof3gxndrg2fhecc6b3dqfzwu Physical review. X 15 1 fd57eb52-4af7-4ba7-a4c8-57a95c69e2d5 Article (Published version) Public Article_scientifique_from_crossref.pdf 1083842 application/pdf CC BY-4.0 e471d824334ece809f8768c21862e3f9bfc40b047e666fa0dd6174335079d6f9 Vignette Public Clipboard-2.jpg 281532 image/png openAccess Faculté des sciences / Section de physique / Département de physique de la matière quantique Faculté des sciences / Section de physique / Groupe de physique appliquée

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Positive Oscillating Magnetoresistance in a van der Waals Antiferromagnetic Semiconductor	Physical review. X			2025	49	83

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