Thermal Transport Measurements of a Shastry-Sutherland Magnet with Capacitive Thermometry

The Shastry-Sutherland magnet SrCu₂(BO₃)₂ has been predicted to host excitations known as triplons which give rise to a thermal Hall conductivity. Measurements of the thermal Hall effect are challenging to make since they require sensitive thermometry at low temperatures and in intense magnetic fields. Most standard methods of measuring temperature are either not sensitive enough or have significant magnetic field induced deviations. We have developed a technique using Oxygen-18 doped Strontium Titanate to make capacitive thermometers which are sensitive at the required temperature range while also not being affected by magnetic fields. By combining this method with more traditional methods of thermometry, we have been able to observe field-dependent thermal properties in SrCu₂(BO₃)₂, including a strongly varying thermal conductivity as well as our exploration of the predicted thermal Hall conductivity.