Heat transport in magnetic fields by quantum spin liquid in the organic insulators EtMe3Sb[Pd(dmit)2]2 and \kappa-(BEDT-TTF)2Cu2(CN)3

TL;DR

This paper investigates how magnetic fields affect heat transport in quantum spin liquids within specific organic insulators, revealing the magnetic field dependence of spinon effective mass and conductivity scaling.

Contribution

It introduces a model near the fermion condensation transition to analyze low-temperature thermal conductivity measurements in frustrated insulators.

Findings

Strong magnetic field dependence of spinon effective mass.

Scaling behavior of thermal conductivity observed.

Good agreement between theoretical calculations and experimental data.

Abstract

Measurements of the low-temperature thermal conductivity collected on insulators with geometrical frustration produce important experimental facts shedding light on the nature of quantum spin liquid composed of spinons. We employ a model of strongly correlated quantum spin liquid located near the fermion condensation phase transition to analyze the exciting measurements of the low-temperature thermal conductivity in magnetic fields collected on the organic insulators EtMe3Sb[Pd(dmit)_2]2 and \kappa-(BEDT-TTF)2Cu2(CN)3. Our analysis of the conductivity allows us to reveal a strong dependence of the effective mass of spinons on magnetic fields, to detect a scaling behavior of the conductivity, and to relate it to both the spin-lattice relaxation rate and the magnetoresistivity. Our calculations and observations are in a good agreement with experimental data.