2025/10/09 by Kumar, Sonu, Bastien, Gaël, Savinov, Maxim +6 · 1 citation
#FOS: Physical sciences #Quantum Physics (quant-ph) #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2510.08746
We report dielectric and magnetoelectric studies of single-crystalline \ceCeMgAl11O19, a Kramers triangular magnet embedded in a polarizable hexaaluminate lattice. In zero magnetic field, the permittivity ε'(T) follows the Barrett law of a quantum paraelectric down to 25 K, below which a broad minimum develops near 3 K without evidence of static ferroelectric or magnetic order. Application of magnetic fields up to \SI9\tesla shifts this minimum to higher temperatures and broadens it, evidencing a tunable magnetoelectric response.The magnetoelectric coupling was characterized using results from magnetization measurements. The anomaly temperature T^*, extracted from the local minimum of ε'(T), exhibits a linear dependence on the squared magnetization M2, consistent with the biquadratic magnetoelectric coupling allowed in centrosymmetric systems. This magnetoelectric effect, mediated by spin-orbit-entangled Kramers doublets interacting with a frustrated antipolar liquid, establishes \ceCeMgAl11O19 as a prototype for exploring quantum magnetoelectricity in frustrated systems.