Theory of the Raman spectra of the Shastry-Sutherland antiferromagnet SrCu2(BO3)2 doped with nonmagnetic impurities

Sylvain Capponi (1, 2) , Didier Poilblanc (1, 2) , F. Mila (3)

1 FFC - Fermions Fortement Corrélés (LPT)
2 LPT - Laboratoire de Physique Théorique
3 UNIL - Université de Lausanne = University of Lausanne

Controlled doping of SrCu$_2$(BO$_3$)$_2$, a faithful realization of the Heisenberg spin-1/2 antiferromagnet on the Shastry-Sutherland lattice, with non-magnetic impurities generates bound-states below the spin gap. These bound-states and their symmetry properties are investigated by exact diagonalisation of small clusters and within a simple effective model describing a spinon submitted to an attractive extended potential. It is shown that Raman spectroscopy is a unique technique to probe these bound-states. Quantitative theoretical Raman spectra are numerically obtained.

Domaines: Autre [cond-mat.other]

Sylvain Capponi, Didier Poilblanc, F. Mila. Theory of the Raman spectra of the Shastry-Sutherland antiferromagnet SrCu2(BO3)2 doped with nonmagnetic impurities. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2009, 80, pp.094407. ⟨10.1103/PhysRevB.80.094407⟩. ⟨hal-00417582⟩