Anomalous Thermal Conductivity and Magnetic Torque Response in the Honeycomb Magnet alpha-RuCl3

Abstract

We report on the unusual behavior of the in-plane thermal conductivity. and torque tau response in the Kitaev-Heisenberg material alpha-RuCl3. kappa shows a striking enhancement with linear growth beyond H = 7 T, where magnetic order disappears, while t for both of the in-plane symmetry directions shows an anomaly at the same field. The temperature and field dependence of kappa are far more complex than conventional phonon and magnon contributions, and require us to invoke the presence of unconventional spin excitations whose properties are characteristic of a field-induced spin-liquid phase related to the enigmatic physics of the Kitaev model in an applied magnetic field.