Speaker
Description
Exploring spin, orbital and topological properties of two-dimensional (2D) materials represents a new platform for realizing novel quantum and spin-based phenomena and device applications. Furthermore, engineering 2D heterostructures by combining the best of different materials in one ultimate unit can offer a plethora of opportunities in spintronics. Furthermore, nontrivial topology in the electronic band structure of quantum materials also makes them potential candidates for emerging technologies. We showed that their unique band structure and lower crystal symmetries can provide an unconventional spin polarized current [1] and out-of-plane spin-orbit torque [2] needed for field-free magnetization switching. The out-of-plane spin Hall conductivity in such 2D quantum materials are estimated to be an order of magnitude higher than the conventional materials.
2D magnets are promising due to their tunable magnetic properties, which can be altered through gating and doping, allowing the strength of magnetic interactions to be tailored for specific applications. We reported above room temperature van der Waals magnet-based spin-valve [3,4] and spin-orbit torque memory [5] devices using all-2D heterostructures. In the latter cases, using a TaIrTe$_4$/Fe$_3$GaTe$_2$ device, we could demonstrate energy-efficient and field-free magnetization switching [5].
Furthermore, we utilized van der Waals magnets with the coexistence of ferromagnetic and antiferromagnetic orders, exhibiting intrinsic exchange bias in the system, which gives rise to canted magnetism [6]. Such canted magnetism facilitates field-free magnetization switching in conventional spin-orbit materials, such as Pt [6,7]. Furthermore, I will present some new findings on orbital torque-induced magnetization switching of van der Waals magnets. These findings open a new platform for realizing devices that utilize van der Waals magnets and all-2D heterostructures.
References:
[1] Advanced Materials 32, 2000818 (2020).
[2] Nature Communications 15 (1), 4649 (2024).
[3]Advanced Materials, 2209113 (2023).
[4] ACS Nano 2024, 18, 7, 5240 (2024).
[5] Arxiv,https://doi.org/10.48550/arXiv.2308.13408
[6] Arxiv,https://doi.org/10.48550/arXiv.2408.13095
[7] ACS Nano 19, 14, 13817–13824 (2025).
