Emergent critical phenomenon in spin-1/2 ferromagnetic-leg ladders: Quasi-one-dimensional Bose-Einstein condensate

摘要

We examine the magnetic-field-induced criticality of phase boundary near saturation field H-c in the spin-1/2 ferromagnetic (FM)-leg ladder 3-Cl-4-F-V [=3-(3-chloro-4-fluorophenyl)-1,5-diphenylverdazyl], the predominant interactions of which arise from FM chains (strong-leg type). Critical temperatures were precisely determined through DC magnetization, specific heat, and magnetocaloric effect measurements. The criticality of 3-Cl-4-F-V is characterized by a linear phase boundary with respect to H-c - H near H = H-c. This behavior is similar to that of another strong-leg-type FM-leg ladder. The universal critical behavior in these strong-leg-type FM-leg ladders is expected to demonstrate the theoretically predicted quasi-one-dimensional Bose-Einstein condensation.