Magnetic-field induced multiferroicity in a quantum critical frustrated spin liquid

TL;DR

This study demonstrates the emergence of multiferroicity in Sul-Cu2Cl4, a quantum spin liquid, induced by magnetic fields, revealing complex phase behavior near quantum criticality through dielectric spectroscopy.

Contribution

It provides the first evidence of magnetic-field induced multiferroicity in a quantum critical frustrated spin liquid, mapping its phase diagram near the quantum-critical point.

Findings

Multiferroicity appears in Sul-Cu2Cl4 under magnetic fields.

The H-T phase diagram shows complex behavior near quantum criticality.

Dielectric spectroscopy confirms polar order in the spiral phase.

Abstract

Dielectric spectroscopy is used to check for the onset of polar order in the quasi one-dimensional quantum spin system Sul-Cu2Cl4 when passing from the spin-liquid state into the ordered spiral phase in an external magnetic field. We find clear evidence for multiferroicity in this material and treat in detail its H-T phase diagram close to the quantum-critical regime.