13.07.2026 Publication: Exchange energy of the ferromagnetic electronic ground state in a monolayer semiconductor MoS2
Article by Nadine Leisgang et. al. published in the scientific magazine Physical Review Letters
(a) Band structure of monolayer MoS2 showing exciton formation at the K and K˜ points and the intervalley scattering via electron-hole exchange. (b) Schematic of the reconstructed band structure containing ferromagnetically ordered itinerant electrons with spin ↓. (c) Schematic of the sample design. FLG stands for few-layer graphene.
Mobile electrons in the semiconductor monolayer MoS2 form a ferromagnetic state at low temperature. By analyzing the optical emission spectrum, we directly measured the energy required to flip a single spin – the exchange energy – within this ordered phase. The surprisingly large exchange energy indicates that the ferromagnetic state is remarkably robust and can remain stable up to temperatures of several tens of Kelvin.
This work was featured in Quantum Women Reseach Spotlight.