Field-induced quantum phase in a frustrated zigzag-square lattice

TL;DR

This paper reports the experimental observation of a field-induced quantum phase transition in a frustrated zigzag-square lattice, demonstrating how external magnetic fields can induce a dimensional reduction and stabilize a quantum state with a 1/2 magnetization plateau.

Contribution

It provides the first experimental realization of a field-induced quantum phase in a frustrated zigzag-square lattice with detailed magnetic behavior analysis.

Findings

Observation of a magnetization plateau at 1/2

Evidence of a phase transition induced by magnetic field

Demonstration of field-induced dimensional reduction

Abstract

This study presents the experimental realization of a spin-1/2 zigzag-square lattice in a verdazyl-based complex, namely ($m$-Py-V-2,6-F$_2$)$[$Cu(hfac)$_2]$. Molecular orbital calculations suggest the presence of five types of frustrated exchange couplings. Our observations reveal an incremental increase in the magnetization curve beyond a critical field, signifying a phase transition from the antiferromagnetic ordered state to a quantum state characterized by a 1/2 plateau. This intriguing behavior arises from the effective stabilization of a zigzag chain by the external fields. These results provide evidence for field-induced dimensional reduction in a zigzag-square lattice attributed to the effects of frustration.