Theory of spin density profile in the magnetization plateaus of SrCu_2(BO_3)_2

TL;DR

This paper develops a microscopic model incorporating spin-lattice interactions to explain the magnetization plateaus and superstructures observed in SrCu2(BO3)2, aligning with recent NMR experimental findings.

Contribution

It introduces a simple adiabatic spin-lattice interaction model to describe the superstructures at magnetization plateaus in SrCu2(BO3)2.

Findings

Reproduces main features of experimental NMR results

Highlights importance of spin-lattice effects in plateau formation

Provides insights into superstructure stabilization at high fields

Abstract

The two-dimensional spin-gap system ${\rm SrCu_2(BO_3)_2}$ shows unique physical properties due to the low-dimensionality character and the strong quantum fluctuations. Experimentally, 1/8-, 1/4-, and 1/3-plateaus have been observed in the magnetization curve under magnetic fields up to 70 Tesla, and the 1/2-plateau is expected to be stabilized at higher magnetic fields. We argue that spin-lattice effects are necessary to describe the superstructures at the plateaus, and we propose a simple microscopic model of spins interacting adiabatically with the lattice to reproduce the main features of the recent experimental results by nuclear magnetic resonance.