Figure 2: Valley-selective CD of monolayer MoS2.
From: Valley-selective circular dichroism of monolayer molybdenum disulphide
(a) Top valence band (blue) and bottom conduction band (pink). The centre hexagon is the Brillouin zone colour-coded by the degree of circular polarization, η(k), as defined in the text. The vector connecting K+ and K− is perpendicular to Mo-S bond in the crystal structure in Fig. 1b. (b) Schematic of phase winding on the MoS2 lattice that gives rise to the chiral optical selectivity. Left panel: the contribution to phase winding from the Bloch lattice phase, where τ=±1 is the valley index, and s=1,2 corresponding to the S and Mo sites (isospin index). Right panel: the phase winding under a threefold rotation. The green axes indicate the rotation of local atomic coordinates that leads to the azimuth dissynchronization.
