Algebraic Charge Dynamics of Quantum Spin Liquid b'-EtMe3Sb[Pd(dmit)2]2

TL;DR

This study investigates the nuclear spin relaxation rates in a quantum spin-liquid candidate, revealing how molecular rotations influence relaxation and demonstrating persistent low-temperature spin dynamics with algebraic temperature dependence.

Contribution

It provides detailed analysis of nuclear spin relaxation in a quantum spin liquid, highlighting the role of molecular rotations and persistent low-temperature spin fluctuations.

Findings

Enhanced 1/T1 due to methyl and ethyl group rotations

Persistent spin dynamics at the Sb site down to lowest temperatures

Algebraic temperature dependence of correlation times

Abstract

Nuclear spin-lattice (1/T1) and spin-spin (1/T2) relaxation rates of the cation sites of a quantum spin-liquid candidate b'-EtMe3Sb[Pd(dmit)2]2 and its deuterated sample are presented. The enhanced 1/T1 of 1H and 2D are well analyzed considering the rotations of methyl- and ethyl-groups of the cation with the activation energies of 200K and 1200K respectively. The 1/T1 and 1/T2 at the Sb site that is located on the 2-fold rotation axis remain active down to the lowest temperature with an algebraic temperature dependence of the correlation time as has been observed in the ac response of the dielectric constants.