Anomalous thermal broadening in the Shastry-Sutherland model and SrCu$_2($BO$_3)_2$

التفاصيل البيبلوغرافية
العنوان: Anomalous thermal broadening in the Shastry-Sutherland model and SrCu$_2($BO$_3)_2$
المؤلفون: Wang, Zhenjiu, McClarty, Paul, Dankova, Dobromila, Honecker, Andreas, Wietek, Alexander
سنة النشر: 2024
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Strongly Correlated Electrons
الوصف: The quantum magnet SrCu$_2($BO$_3)_2$ and its remarkably accurate theoretical description, the spin-$1/2$ Shastry-Sutherland model, host a variety of intriguing phenomena such as a dimer ground state with a nearly flat band of triplon excitations, a series of magnetization plateaux, and a possible pressure-induced deconfined quantum critical point. One open puzzle originating from inelastic neutron scattering and Raman experiments is the anomalous broadening of the triplon modes at relatively low temperatures compared to the triplon gap $\Delta$. We demonstrate that the experimentally observed broadening is captured by the Shastry-Sutherland model. To this end, we develop a numerical simulation method based on matrix-product states to simulate dynamical spectral functions at nonzero temperatures accurately. Perturbative calculations identify the origin of this phenomenon as a small energy scale compared to $\Delta$ between single triplon and bound triplon states at the experimentally relevant model parameters.
Comment: 5 pages, 5 figures
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2405.18475
رقم الأكسشن: edsarx.2405.18475
قاعدة البيانات: arXiv