Figure 4. Zeeman splitting and diamagnetic shift in bulk WS₂.

(a) Intensity of reflected σ⁺ light from the A exciton in bulk WS₂ at 4 K, using B=0, +60 and −60 T. (b) Energies of the Zeeman-split exciton transitions, E⁺ and E⁻. (c) The measured exciton splitting (E⁺−E⁻), corresponding to g=−3.33. For comparison, the red line shows the valley Zeeman splitting measured in monolayer WS₂ (cf. Fig. 2f). (d) The average energy (E⁺+E⁻)/2 showing a diamagnetic shift (0.64 μeV T⁻²) that is twice as large as that measured in monolayer WS₂ (red line; cf. Fig. 2g).