# Quasi-one-dimensional Bose-Einstein Condensation in the Spin-1/2 Ferromagnetic-leg Ladder 3-I-V

## TL;DR

This study investigates quantum criticality in a ferromagnetic-leg ladder compound, revealing quasi-one-dimensional Bose-Einstein condensation behavior near the phase transition, supported by experimental phase boundary data.

## Contribution

It provides the first experimental candidate demonstrating quasi-1D Bose-Einstein condensation in a ferromagnetic-leg ladder system.

## Key findings

- Phase boundary follows a power-law near the critical field.
- Evidence supports quasi-1D Bose-Einstein condensation.
- First experimental realization of this phenomenon in such a system.

## Abstract

Quantum criticality of the spin-1/2 ferromagnetic-leg ladder 3-I-V [=3-(3-iodophenyl)-1,5-diphenylverdazyl] has been examined with respect to the antiferromagnetic to paramagnetic phase transition near the saturation field $H_{c}$. The phase boundary $T_{c}(H)$ follows the power-law $T_{c}(H)\propto H_{c}-H$ for a wide temperature range. This characteristic behavior is discussed as a quasi-one-dimensional (quasi-1D) Bose-Einstein condensation, which is predicted theoretically for weakly coupled quasi-1D ferromagnets. Thus, 3-I-V provides the first promising candidate for this attractive prediction.