Low Energy Excitations of Yb4As3 in a Magnetic Field

TL;DR

This paper investigates how magnetic fields influence low energy excitations in Yb4As3, revealing nearly isotropic interactions and a field-induced gap, aligning with experimental data and proposing further tests.

Contribution

It demonstrates that Yb4As3's magnetic interactions are nearly isotropic Heisenberg type and explains the field-induced gap due to small anisotropy, supported by experimental agreement.

Findings

Magnetic field affects low energy excitations in Yb4As3.

Yb3+ ions exhibit nearly isotropic Heisenberg spin-1/2 interactions.

A small anisotropy causes a gap to open under magnetic field.

Abstract

We discuss the effects of an applied magnetic field on the low energy excitations in the low temperature phase of Yb4As3. We show also why the magnetic interaction of the Yb{3+} ions is nearly of an isotropic Heisenberg spin-1/2 type. A small anisotropy due to an intrachain dipolar interaction leads to the opening of a gap when a magnetic field is applied. The model agrees with available experimental data. Simple experiments are suggested in order to further test the present theory.