Spin-polaron excitations in a doped Shastry-Sutherland model

Abstract

Using variational algorithm on an infinite Shastry-Sutherland (SS) lattice we show that the introduction of a static nonmagnetic impurity into a dimerized ground state leads to a formation of a small, localized spin polaron surrounding the impurity site. Due to a particular symmetry of the SS lattice, the polaron is extremely anisotropic with a short spatial extent. The presence of nonmagnetic impurities leads to a formation of pronounced in-gap peaks in the dynamical spin structure factor, which we attribute to the spin-doublet excitations of a single unpaired spin $S=1/2$ surrounded by triplet fluctuations. Our results are relevant for the description of SrCu${}_2$(BO${}_3$)${}_2$ compound when doped with nonmagnetic atoms at Cu sites.

5 pages, 5 figures

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Cited by in corpus (8)

• Numerical approach to low-doping regime of the t-J model
• Dynamics and Instabilities of the Shastry-Sutherland Model
• Correlated decay of triplet excitations in the Shastry-Sutherland compound SrCu${}_2$(BO${}_3$)${}_2$
• Emergent Bound States and Impurity Pairs in Chemically Doped Shastry-Sutherland System
• Persistence of magnons in a site-diluted dimerized frustrated antiferromagnet
• Theory of the Raman spectra of the Shastry-Sutherland antiferromagnet SrCu${}_2$(BO${}_3$)${}_2$ doped with nonmagnetic impurities
• Real Space Imaging of Spin Polarons in Zn Doped SrCu2(BO3)2
• Insulator-metal transition and quasi-flat-band of Shastry-Sutherland lattice