The effect of Dzyaloshinskii-Moriya interactions on the phase diagram and magnetic excitations of SrCu2(BO3)2

TL;DR

This paper investigates how Dzyaloshinskii-Moriya interactions influence the phase diagram and magnetic excitations in SrCu2(BO3)2, using variational and bond-wave methods to match experimental spectra.

Contribution

It introduces a variational approach to map the phase diagram including anisotropies and develops a bond-wave method to compute excitation spectra, aligning with experimental observations.

Findings

Reproduces zero field splittings in spectra

Identifies persistent gap at high fields

Maps phase diagram with anisotropies

Abstract

The orthogonal dimer structure in the SrCu2(BO3)2 spin-1/2 magnet provides a realization of the Shastry-Sutherland model. Using a dimer-product variational wave function, we map out the phase diagram of the Shastry-Sutherland model including anisotropies. Based on the variational solution, we construct a bond-wave approach to obtain the excitation spectra as a function of magnetic field. The characteristic features of the experimentally measured neutron and ESR spectra are reproduced, like the anisotropy induced zero field splittings and the persistent gap at higher fields.