Spin Frustration and a `Half Fire, Half Ice' Critical Point from Nonuniform $g$-Factors

TL;DR

This paper reveals a new type of spin frustration caused by nonuniform g-factors in ferromagnets, leading to unique magnetic states including a 'half fire, half ice' critical point with partial order and disorder.

Contribution

It introduces a novel mechanism for spin frustration via nonuniform g-factors, predicting exotic magnetic states and critical points not previously documented.

Findings

Identification of a 'half fire, half ice' critical point at zero temperature.

Prediction of frustration effects in copper-iridium oxides like Sr₃CuIrO₆.

Potential realization of these states in antiferromagnets, lattice gases, and neural systems.

Abstract

It is demonstrated that novel spin frustration can be induced in ferromagnets with nonuniform Land\'{e} $g$-factors. The frustrated state is characterized by a mutual interplay of typical ferromagnetic (FM) and antiferromagnetic (AF) features, such as the zero-field susceptibility being FM-like at low temperatures but AF-like at high temperatures. It is also found to contain an exotic zero-temperature `half fire, half ice' critical point at which the spins on one sublattice are fully disordered and on the other one are fully ordered. We suggest that such frustration may occur in a number of copper-iridium oxides such as Sr$_3$CuIrO$_6$. We also anticipate a realization of the frustration and `partial fire, partial ice' states in certain antiferromagnets, lattice gas, and neuron systems.