Fig. 2
From: The nature of spin excitations in the one-third magnetization plateau phase of Ba3CoSb2O9
Scheme of NLSW theory for the 1/3 magnetization plateau in the quasi-2D TLHAFM. a Illustration of the procedure used to compute the spectrum. The filled and open star symbols represent the target quasi-2D quantum system and its naive classical limit, respectively. The spin structures favored by quantum fluctuation are shown on the Jc = 0 plane. b LSW spectrum along the high-symmetry direction of the Brillouin zone evaluated for S = 1/2, Jc = 0, Δ = 0.85 and hred = 3JS, where the UUD state is a classical ground state (CGS). c–e NLSW spectra for Jc = 0 and Δ = 0.85 with (c) hred = 3JS, (d) hred = 2.7JS, and (e) hred = 3.3JS. f, g NLSW spectra for Jc/J = 0.09 and Δ = 0.85 with (f) hred = 2.7JS and (g) hred = 3.3JS
