Coupled frustrated ferromagnetic and antiferromagnetic quantum spin chains in the quasi-one-dimensional mineral antlerite, Cu$_3$SO$_4$(OH)$_4$

TL;DR

Antlerite, Cu$_3$SO$_4$(OH)$_4$, is a quasi-one-dimensional magnetic material with tunable frustration, showing potential for exploring novel magnetic states due to its sensitivity to atomic details.

Contribution

This study identifies antlerite as a tunable platform for magnetic frustration, revealing its sensitive dependence on atomic structure and potential for diverse magnetic phases.

Findings

Low-temperature magnetic state resembles spinon-magnon mixing.

Density functional theory shows ground state sensitivity to atomic positions.

Each chain is near a phase transition, enabling tunability.

Abstract

Magnetic frustration, the competition among exchange interactions, often leads to novel magnetic ground states with unique physical properties which can hinge on details of interactions that are otherwise difficult to observe. Such states are particularly interesting when it is possible to tune the balance among the interactions to access multiple types of magnetic order. We present antlerite, Cu$_3$SO$_4$(OH)$_4$, as a potential platform for tuning frustration. Contrary to previous reports, the low-temperature magnetic state of its three-leg zigzag ladders is a quasi-one-dimensional analog of the magnetic state recently proposed to exhibit spinon-magnon mixing in botallackite. Density functional theory calculations indicate that antlerite's magnetic ground state is exquisitely sensitive to fine details of the atomic positions, with each chain independently on the cusp of a phase transition, indicating an excellent potential for tunability.