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arXiv · 2303.17038

Programming Correlated Magnetic States via Gate Controlled Moir\'e Geometry

Eric Anderson·Feng-Ren Fan·Jiaqi Cai·William Holtzmann·Takashi Taniguchi·Kenji Watanabe·Di Xiao·Wang Yao·Xiaodong Xu
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Abstract

Understanding quantum many-body systems is at the heart of condensed matter physics. The ability to control the underlying lattice geometry of a system, and thus its many-body interactions, would enable the realization of and transition between emergent quantum ground states. Here, we report in-situ gate switching between honeycomb and triangular lattice geometries of an electron many-body Hamiltonian in R-stacked MoTe2 moir\'e bilayers, resulting in switchable magnetic exchange interactions. At zero electric field, we observe a correlated ferromagnetic insulator near one hole per moir\'e unit cell ({\nu}=-1), i.e., a quarter-filled honeycomb lattice, with a widely tunable Curie temperature up to 14K. Fully polarizing layer pseudospin via electric field switches the system into a half-filled triangular lattice with antiferromagnetic interactions. Further doping this layer-polarized superlattice introduces carriers into the empty layer, tuning the antiferromagnetic exchange interaction back to ferromagnetic. Our work demonstrates R-stacked MoTe2 moir\'es to be a new laboratory for engineering correlated states with nontrivial topology.

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Eric Anderson, Feng-Ren Fan, Jiaqi Cai, William Holtzmann, Takashi Taniguchi, Kenji Watanabe, Di Xiao, Wang Yao, Xiaodong Xu. 2023-03-29. Programming Correlated Magnetic States via Gate Controlled Moir\'e Geometry. https://doi.org/10.1126/science.adg4268

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