Boddison-Chouinard Justin, Korkusinski Marek, Bogan Alex, Barrios Pedro, Waldron Philip, Watanabe Kenji, Taniguchi Takashi, Pawłowski Jarosław, Miravet Daniel, Hawrylak Pawel, Luican-Mayer Adina, Gaudreau Louis
Quantum and Nanotechnologies Research Centre, National Research Council Canada, Ottawa, Ontario, K1A 0R6, Canada.
Department of Physics, University of Ottawa, Ottawa, Ontario, K1N 9A7, Canada.
Sci Adv. 2025 May 9;11(19):eadu4696. doi: 10.1126/sciadv.adu4696. Epub 2025 May 7.
Monolayer transition metal dichalcogenides have emerged as prominent candidates to explore the complex interplay between spin and valley degrees of freedom. Their strong spin-orbit interaction and broken inversion symmetry lead to the spin-valley locking effect, in which carriers occupying the and ' valleys of the reciprocal space must have opposite spins. This effect is particularly strong for holes due to a larger spin-orbit gap in the valence band. By reducing the dimensionality of a monolayer of WSe to 1D via electrostatic confinement, we demonstrate that spin-valley locking and strong hole-hole interactions lead to a ferromagnetic state where hole transport is spin-valley polarized, even without an applied magnetic field. A massive Dirac fermion model in the Hartree-Fock approximation reveals that many-body hole-exchange interactions lead to this polarized ground-state. This observation opens the possibility of implementing a robust and stable valley-polarized system, essential in valleytronic applications.
单层过渡金属二硫族化合物已成为探索自旋和能谷自由度之间复杂相互作用的重要候选材料。它们强烈的自旋轨道相互作用和破缺的空间反演对称性导致了自旋-能谷锁定效应，即占据倒易空间中K和K'能谷的载流子必须具有相反的自旋。由于价带中较大的自旋轨道能隙，这种效应对于空穴尤为显著。通过静电限制将单层WSe₂的维度降至一维，我们证明自旋-能谷锁定和强空穴-空穴相互作用导致了一种铁磁态，其中空穴输运是自旋-能谷极化的，即使在没有外加磁场的情况下也是如此。哈特里-福克近似下的大质量狄拉克费米子模型表明，多体空穴交换相互作用导致了这种极化基态。这一发现为实现一个稳健且稳定的能谷极化系统开辟了可能性，这在谷电子学应用中至关重要。
