Quasi-one-dimensional Spin Dynamics in a Molecular Spin Liquid System

TL;DR

This study uses ESR and muSR measurements, combined with theoretical calculations, to reveal that the molecular system exhibits quasi-one-dimensional spin dynamics, challenging previous triangular lattice frustration explanations for its quantum spin liquid behavior.

Contribution

It demonstrates that the quantum spin liquid behavior in beta'-EtMe3Sb[Pd(dmit)2]2 is primarily due to 1D spin liquid characteristics from dimensional reduction, supported by combined experimental and theoretical analysis.

Findings

ESR and muSR indicate q1D spin dynamics

Anisotropy direction contradicts previous theories

Dimensional reduction explains QSL behavior

Abstract

The molecular triangular lattice system, beta'-EtMe3Sb[Pd(dmit)2]2, is considered as a candidate material for the quantum spin liquid (QSL) state, although ongoing debates arise from recent controversial results. Here, the results of electron spin resonance (ESR) and muon spin relaxation (muSR) measurements on beta'-EtMe3Sb[Pd(dmit)2]2 are presented. Both results indicate characteristic behaviors related to quasi-one-dimensional (q1D) spin dynamics, whereas the direction of anisotropy found in ESR is in contradiction with previous theories. We succeed in interpreting the experiments by combining density-functional theory calculations and analysis of the effective model taking into account the multi-orbital nature of the system. While the QSL-like origin of beta'-EtMe3Sb[Pd(dmit)2]2 was initially attributed to the magnetic frustration of the triangular lattice, it appears that the primary origin is a 1D spin liquid resulting from the dimensional reduction effect.