Dielectric relaxation in the quantum multiferroics Rb$_2$Cu$_2$Mo$_3$O$_{12}$ and Cs$_2$Cu$_2$Mo$_3$O$_{12}$

D. Flavián; P. A. Volkov; S. Hayashida; K. Yu. Povarov; S. Gvasaliya; P. Chandra; A. Zheludev

paper

Dielectric relaxation in the quantum multiferroics Rb $_{2}$ Cu $_{2}$ Mo $_{3}$ O $_{12}$ and Cs $_{2}$ Cu $_{2}$ Mo $_{3}$ O $_{12}$

arXiv:2406.12690

Abstract

Motivated by the recent discovery of dielectric relaxation by quantum critical magnons in Cs $_{2}$ Cu $_{2}$ Mo $_{3}$ O $_{12}$ , we conduct a detailed analysis of its dielectric response and compare it to that in the isostructural compound Rb $_{2}$ Cu $_{2}$ Mo $_{3}$ O $_{12}$ . Measurements in the vicinity of the field-induced magnon softening show that its description in terms of 3D Bose-Einstein condensation of magnons quantum critical point is unaltered by the presence of dielectric relaxation. We also demonstrate the existence of dielectric relaxation anomalies at 19 K in Rb $_{2}$ Cu $_{2}$ Mo $_{3}$ O $_{12}$ and discuss the implications for the microscopic origin of dielectric activity in two compounds.

8 pages, 10 figures

Dielectric relaxation in the quantum multiferroics Rb2​Cu2​Mo3​O12​ and Cs2​Cu2​Mo3​O12​

Abstract

Dielectric relaxation in the quantum multiferroics Rb $_{2}$ Cu $_{2}$ Mo $_{3}$ O $_{12}$ and Cs $_{2}$ Cu $_{2}$ Mo $_{3}$ O $_{12}$