Thermal Hall in Insulating Parent Compounds of Cuprates

The observation of a sizable thermal Hall effect in a variety of insulating materials has raised fundamental questions about how phonons can acquire chirality in the absence of free charge carriers. This phenomenon is particularly intriguing in the insulating parent compounds of high-temperature superconducting cuprates, as it might provide insights into the pseudogap phase [1]. We have performed thermal Hall measurements on antiferromagnetic La₂CuO₄ with different Néel temperatures, and on insulating YBa₂Cu₃O_x (x ≈ 6.1). In addition, we have investigated the influence of the thermal Hall response of various metallic components on the measured signal to ensure accurate measurement of the thermal Hall effect in these materials.

[1]G. Grissonnanche et al. Nature 571, 376-380 (2019).