Competing Orders and Superconductivity in the Doped Mott Insulator on the Shastry-Sutherland Lattice

TL;DR

This study investigates the doped Mott insulator on the Shastry-Sutherland lattice using the t-J model, revealing competing orders and superconducting phases, with implications for doped SrCu$_2$(BO$_3$)$_2$.

Contribution

It applies U(1) slave-boson mean field theory to analyze competing orders and superconductivity in the doped Shastry-Sutherland lattice, highlighting the coexistence of different broken symmetry states.

Findings

Existence of superconducting phases with coexisting symmetry-breaking orders.

Strong competition between different broken symmetry states.

Relevance to doped SrCu$_2$(BO$_3$)$_2$ material.

Abstract

Quantum antiferromagnets on geometrically frustrated lattices often allow a number of unusual paramagnetic ground states. The fate of these Mott insulators upon doping is an important issue that may shed some light on the high $T_c$ cuprate problem. We consider the doped Mott insulator on the Shastry-Sutherland lattice via the t-J model. The U(1) slave-boson mean field theory reveals the strong competition between different broken symmetry states. It is found that, in some ranges of doping, there exist superconducting phases with or without coexisting translational-symmetry- breaking orders such as the staggered flux or dimerization. Our results will be directly relevant to SrCu$_2$(BO$_3$)$_2$ when this material is doped in future.