Ultra spin liquid in Lu3Cu2Sb3O14

Abstract

We analyze recent measurements of C/T, specific heat C divided by temperature T, of a recently observed ultra spin liquid. The measurements are carried out in magnetic fields on the triangular lattice compound Lu3Cu2Sb3O14. We show that the obtained heat capacity C-mag formed by the ultra spin liquid as a function of temperature T vs. magnetic field B behaves very similar to the electronic specific heat C-el of the HF metal YbRh2Si2 and the quantum magnet ZnCu3(OH)(6)Cl-2. We demonstrate that the effective mass of spinon M* proportional to C-mag/T exhibits the universal scaling coinciding with scaling observed in heavy-fermion (HF) metals and in ZnCu3(OH)(6)Cl-2. Based on these observations we conclude that a strongly correlated spin liquid determines the thermodynamic properties of the ultra spin liquid of Lu3Cu2Sb3O14. Copyright (C) 2021 EPLA