Study of 2D magnons in few-layer and twisted double bilayer of chromium triiodide

Two-dimensional (2D) van der Waals magnets offer a highly tunable platform for exploring magnetic, magnetoelectric, and magneto-optical properties in reduced dimensions. The recent advancement in twist engineering has further enriched the landscape of magnetic order and related phenomena in 2D. However, while static magnetic properties have been extensively studied, investigations into magnetic excitations, specifically magnons, remain limited in 2D magnets. In this work, we systematically investigate magnon properties in both natural few-layer and twisted double-bilayer chromium triiodide (CrI₃) using magneto-Raman spectroscopy. Our study comprehensively reveals the energy, selection rules, and magnetic field-dependence of magnons in 1-4L and twisted CrI₃. Additionally, we will highlight the contrast between natural and twisted CrI₃ to discuss the role of twist engineering in spin interactions.