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

TL;DR

This study investigates the critical magnetic behavior of a spin-1/2 ferromagnetic-leg ladder, revealing a linear phase boundary near saturation and supporting the theoretical prediction of quasi-one-dimensional Bose--Einstein condensation.

Contribution

It provides precise experimental evidence of the critical phase boundary behavior in ferromagnetic-leg ladders, linking it to the universal quasi-one-dimensional Bose--Einstein condensation theory.

Findings

Critical temperature determined accurately through magnetization and heat measurements.

Linear phase boundary observed near saturation field.

Results support the theory of quasi-one-dimensional Bose--Einstein condensation.

Abstract

We examine the magnetic-field-induced criticality of phase boundary near saturation field $H_{\mathrm{c}}$ 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 $H_{\mathrm{c}}-H$ near $H\,=\,H_{\mathrm{c}}$. 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.