Emergence of One-Dimensional Physics from the Distorted Shastry-Sutherland Lattice

TL;DR

This paper investigates how a modified Shastry-Sutherland model exhibits a transition to one-dimensional physics, revealing nearly decoupled Haldane chains and the stability of the plaquette solid phase.

Contribution

It introduces a variant of the SS model with two types of dimers, demonstrating dimensional reduction and the persistence of the plaquette phase.

Findings

Emergence of nearly decoupled S=1 Haldane chains along diagonals.

Stability of the intermediate plaquette solid phase in a finite parameter region.

Dimensional reduction occurs over a large parameter range.

Abstract

Motivated by the on-going investigation of SrCu$_2$(BO$_3$)$_2$ under pressure, we study a variant of the two-dimensional Shastry-Sutherland (SS) spin-1/2 model with two types of dimers. Combined with the frustration of the SS model, this modification induces, in a large parameter range, a dimensional reduction at low energies, with nearly decoupled effective S=1 Haldane chains forming along one of the diagonals of the lattice. We also present evidence that the intermediate plaquette solid phase of the undistorted SS model remains stable in a finite region of the phase diagram.