November 07, 2022
Minneapolis, United States
Tuning exchange interactions in 1T VSe2 monolayer by alkali metal adsorption and electride substrate
The manipulation of exchange interactions in two-dimensional magnets has fundamental research value and potential applications. Based on first-principles calculations, the exchange interactions in experimental controversial ferromagnetic 1T-VSe2 monolayer 1,2 are systematically studied. It is found that three shells of nearest-neighbor Heisenberg exchange interactions and higher-order interactions are crucial for an accurate description of the ferromagnetism in 1T-VSe2 monolayer. Based on the understanding of tuning the magnetic interactions and the magnetic ground state in 1T-VSe2 monolayer by external factors, two modulation methods, alkali metal Lithium adsorption and electride Ca2N substrate, are proposed. In both systems, the strongly frustrated Heisenberg exchange interactions compete with higher-order exchange interactions, Dzyaloshinskii-Moriya interaction and magnetocrystalline anisotropy, leading to complex magnetic ground states, such as antiferromagnetic spin spiral, periodical antiferromagnetic cycloidal state and double row-wise antiferromagnetic states. These results highlight the effective manipulation of exchange interactions in two-dimensional magnets.
This work was supported by the National Natural Science Foundation of China (51871161 and 52071233). References
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