High-resolution measurements of thermal conductivity matrix and search for thermal Hall effect in La₂CuO₄

We investigated the longitudinal thermal conductivity κ_xx and thermal Hall conductivity κ_xy in La₂CuO₄ at temperatures T between 2 and 20 K in magnetic fields H up to 10 T. Within the temperature and field intervals studied, we do not resolve any thermal Hall signal with a conservative upper bound of [Formula: see text] [Formula: see text]. The longitudinal thermal conductivity [Formula: see text] agrees well with previous reports, in both its magnitude and T dependence. Both [Formula: see text] and [Formula: see text] were measured using the field-swept protocol. To achieve high resolution, we carefully took into account relaxation effects after each step-increase in H. At low T, we find a weak linear decrease in [Formula: see text] vs. H, as well as weak hystereses near the metamagnetic transitions of the spins.