Oral: Understanding the single-parameter scaling behavior across Neel temperature in the honeycomb antiferromagnet BCAO

The layered honeycomb material BaCo₂(AsO₄)₂ (BCAO) has been of topical interest because of its relation to Kitaev physics. Using thermal transport to probe how magnetic excitations interact with phonons in the magnetically disordered regime, we have uncovered a single-parameter scaling behavior in its thermal conductivity in an in-plane magnetic field B, along with the largest percentage increase under field among all magnetic insulators previously reported. Further investigation shows that the scaling extends to low temperatures into the magnetically disordered phase above the critical field with appropriate normalization, in the non-analytic form exp(-1/gx) where x=μ_BB/k_BT and g is a constant. We propose a simple physical picture that may account for the scaling behavior and the exponential function.