Fig. 5.

Evolving correlations in a magnetic field. With Γ/K = −0.325 and Γ′ = −0.1, quantities computed in the two-leg honeycomb strip with DMRG are plotted as a function of a 5° field for system sizes N = 100, 200, 300, 400 and infinite DMRG (iDMRG) as solid red line. a χ_h displays two peaks which sharpen with increasing system size. These transitions separate ZZ magnetic order and the PS from the intervening KSL. b Plaquette–plaquette correlations $⟨W_p{W}_{p\prime }⟩$ are small within the ZZ and polarized phases, and become appreciable within the KSL. c Conversely, the xx spin–spin correlations 〈S^xS^x〉 are small within the KSL and large in the magnetically ordered phases. d Sharp changes in the zz spin–spin correlations are seen across the phase boundaries, and display a finite value consistent with a KSL in field. Spin and plaquette correlations are evaluated at the largest separation accessible in each cluster