Tracking the evolution from isolated dimers to many-body entanglement in NaLu$_x$Yb$_{1-x}$Se$_2$

TL;DR

This study investigates how magnetic properties evolve in NaLu$_x$Yb$_{1-x}$Se$_2$ as it transitions from isolated magnetic ions to a correlated many-body lattice, revealing insights into spin dimerization and entanglement.

Contribution

It provides a systematic synthesis and characterization of NaLu$_x$Yb$_{1-x}$Se$_2$, highlighting the evolution of magnetic interactions and entropy crossover from dilute ions to a dense magnetic lattice.

Findings

Entropy crossover from isolated ions to correlated lattice

Estimated single ion anisotropy and dimer exchange couplings

Observation of magnetic evolution with composition

Abstract

We synthesize homogeneous compositions of NaLu$_x$Yb$_{1-x}$Se$_2$, connecting non-magnetic NaLuSe$_2$ to the triangular lattice spin liquid candidate NaYbSe$_2$. Thermal and magnetic properties are studied as the system evolves from one with dilute magnetic defects to one of a dense magnetic lattice. The field and temperature dependent heat capacity show the carriers of entropy crossover from isolated magnetic ions to a correlated lattice borne from spin dimers. For the dilute system we estimate the single ion anisotropy $(g_\perp/g_\parallel =3.13)$ and also the dimer exchange couplings $J_\parallel(=5.4$~K) and $J_\perp(=9.6$~K), in order to draw comparison to the half-doped and full magnetic compounds.