Thermal conductivity of Ho2Ti2O7 along the [111] direction
W. H. Toews, Songtian S. Zhang, K. A. Ross, H. A. Dabkowska, B. D. Gaulin, and R. W. Hill
Accepted
Thermal transport measurements have been made on the spin-ice material Ho$_{2}$Ti$_{2}$O$_{7}$ in an applied magnetic field with both the heat current and field parallel to the [111] direction for temperatures from 50 mK to 1.2 K. A large magnetic field $> 6$ T is applied to suppress the magnetic contribution to the thermal conductivity in order to extract the lattice conductivity. The low field thermal conductivity thus reveals a magnetic field dependent contribution to the conductivity which both transfers heat and scatters phonons. We interpret these magnetic excitations as monopole-like excitations and describe their behaviour via existing Debye-H\"{u}ckel theory.