Speaker
Description
In the last decades, proximity effects in graphene-based van der Waals heterostructures have acquired significant attention for their high tunability [1]. Here we study current induced spin accumulation in graphene proximitized by monolayer of 1T-TaS$_{2}$. In such heterostructure, the proximity-induced spin-orbit coupling in the graphene is directly related to the correlated electronic states due to the emergence of charge density wave in 1T-TaS$_{2}$ [2] at low temperatures [3].
The current-induced spin accumulation in the proximitized graphene is directly related to the charge to spin conversion efficiency. The spin accumulation has been calculated in linear Kubo response regime as a function of chemical potential for different perpendicularly applied electric fields. The effective Hamiltonian considers low energy $\pi$ bands and proximity induced intrinsic and Rashba spin-orbit coupling terms. We studied charge to spin conversion efficiency for different graphene/1T-TaS$_2$ and 1T-TaS$_2$/graphene/1T-TaS$_2$ stacking configurations and investigated the effect of the perpendicular electric field on conventional and unconventional Rashba-Edelstein effect. We found that for the specific stacking preserving the horizontal mirror plane symmetry, the perpendicular electric field can be used as an effective control knob to switch sign of the spin accumulation.
Acknowledgements
This work has been funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V05-00008.
References
[1] M. Gmitra and J. Fabian, “Proximity Effects in Bilayer Graphene on Monolayer WSe$_2$: Field-Effect Spin Valley Locking, Spin-Orbit Valve, and Spin Transistor,” Physical Review Letters, vol. 119, no. 14. American Physical Society (APS), Oct. 04, 2017. doi: 10.1103/physrevlett.119.146401.
[2] K. Szałowski, M. Milivojević, D. Kochan, and M. Gmitra, “Spin–orbit and exchange proximity couplings in graphene/1T-TaS$_2$ heterostructure triggered by a charge density wave,” 2D Materials, vol. 10, no. 2. IOP Publishing, p. 025013, Feb. 23, 2023. doi: 10.1088/2053-1583/acbb19.
[3] D. C. Miller, S. D. Mahanti, and P. M. Duxbury, “Charge density wave states in tantalum dichalcogenides,” Physical Review B, vol. 97, no. 4. American Physical Society (APS), Jan. 17, 2018. doi: 10.1103/physrevb.97.045133.
