Quantum spin liquid ground state in the disorder free triangular lattice NaYbS$_2$

TL;DR

This study provides evidence that NaYbS$_2$, a structurally ideal triangular lattice with effective spin $J_{eff}=1/2$, exhibits no magnetic order down to very low temperatures, making it a promising quantum spin liquid candidate.

Contribution

The paper demonstrates that NaYbS$_2$ is a disorder-free triangular lattice system showing no magnetic order, advancing the search for quantum spin liquids.

Findings

No long-range magnetic order down to 0.05 K.

NaYbS$_2$ is structurally ideal and disorder-free.

Supports the quantum spin liquid ground state hypothesis.

Abstract

Rare-earth delafossites were recently proposed as promising candidates for the realization of an effective $S$=1/2 quantum spin liquid (QSL) on the triangular lattice. In contrast to the most actively studied triangular-lattice antiferromagnet YbMgGaO$_4$, which is known for considerable structural disorder due to site intermixing, NaYbS$_2$ delafossite realizes structurally ideal triangular layers. We present detailed $\mu$SR studies on this regular (undistorted) triangular Yb sublattice based system with effective spin $J_{\mathrm{eff}}=1/2$ in the temperature range 0.05 - 40 K. Zero-field (ZF) and longitudinal field (LF) $\mu$SR studies confirm the absence of any long range magnetic order state down to 0.05K ($\sim J$/80). Current $\mu$SR results together with the so far available bulk characterization data suggest that NaYbS$_2$ is an ideal candidate to identify QSL ground state.