Dynamical spin response of electron doped Mott insulators on a triangular lattice

TL;DR

This study investigates the spin dynamics of electron doped Mott insulators on a triangular lattice using the $t-J$ model, revealing the absence of universal behaviors seen in square lattices and showing temperature-dependent spin relaxation rates consistent with experiments.

Contribution

It demonstrates the different spin dynamic behaviors on a triangular lattice compared to square lattices, highlighting the presence of a normal state gap and temperature-dependent relaxation rates.

Findings

Absence of universal dynamical spin structure factor behaviors on a triangular lattice.

Reduction of 1/T₁T with decreasing temperature above 50K.

Curie-Weiss-like behavior of spin relaxation rate below 50K.

Abstract

The spin dynamics of electron doped Mott insulators on a triangular lattice is studied based on the $t-J$ model. It is found that the particularly universal behaviors of integrated dynamical spin structure factor seen in the doped Mott insulators on a square lattice, are absent in the doped Mott insulators on a triangular lattice, indicating the presence of the normal state gap. As a result, the spin-lattice relaxation rate 1/$T_{1}$ divided by $T$ reduces with decreasing temperatures in the temperature region above 0.2$J$$\approx$50K, then follows a Curie-Weiss-like behavior at the temperature less than 50K, in qualitative agreement with experimental observations.