• Scanning tunneling spectroscopy reveals opposite layer polarizations of the K valley at different lattice sites in twisted WSe2.
• Experimental results align with theoretically predicted layer-skyrmion textures.
• Study establishes a direct correlation between the local density of states in real space and the topology of the topmost moiré band.

A recent study published in Nature Physics reports the discovery of experimental signatures of skyrmion textures in the layer degree of freedom of rhombohedral-stacked twisted WSe2 homobilayers. Using scanning tunnelling spectroscopy (STS), researchers were able to separately resolve the Γ-valley and K-valley moiré electronic states, revealing opposite layer polarizations of the K valley at two different lattice sites with opposite stacking order within the moiré unit cell. These findings are consistent with theoretically predicted layer-skyrmion textures and provide valuable insights into the band topology of these materials.

• What: Experimental observation of layer skyrmions in twisted WSe2 homobilayers, and the implications for band topology.
• Who: Researchers from the University of Texas at Austin, The University of Hong Kong, National Yang Ming Chiao Tung University, and Pennsylvania State University, among others.
• When: Published May 1, 2025; Received September 19, 2024; Accepted March 14, 2025
• Where: Research conducted in various labs across the US and Asia.

The study provides crucial experimental validation for the theoretical understanding of layer skyrmions in twisted WSe2 bilayers. The use of scanning tunneling spectroscopy to resolve the valley-dependent moiré electronic states allowed for direct observation of the layer polarization. This research builds upon previous work on twisted transition-metal dichalcogenides, contributing to the growing field of moiré materials and their potential for novel electronic and topological properties. The correlation established between the local density of states and the band topology opens avenues for further exploration of these materials.

This study offers significant experimental evidence supporting the existence of layer skyrmions in twisted WSe2 homobilayers and their connection to band topology. The use of STS provides a powerful tool for probing the electronic structure of these materials. Further research can explore the potential applications of these findings in developing novel electronic devices and understanding fundamental topological phenomena.