Thermally populated versus field-induced triplon bound states in the Shastry-Sutherland lattice SrCu2(BO3)2

Abstract The Shastry–Sutherland compound SrCu 2 (BO 3 ) constituting orthogonally coupled dimers harbors an S = 0 singlet ground state. confluence of strong interdimer interaction and frustration engenders a spectrum low-energy excitations including localized triplons as well triplet bound states. Their dynamics are controlled by external magnetic field temperature. Here, we employ high-field Raman spectroscopy to map the temperature evolution such bosonic composite quasiparticles on approaching 1/8 magnetization plateau. Our study unveils that thermal fluctuations show remarkably similar effects in melting states, but disparate their fine spectral shapes. This, together with anti-crossing two states intermediate B 10 − 16 T, is discussed terms correlated frustrated, interacting bosons.