Thermal Hall Effect Measurements on UPt₃

The heavy fermion material UPt₃ is arguably the best understood unconventional superconductor to date, and has been shown to possess multiple superconducting phases [1,2]. Despite this, the symmetry of the superconducting order parameter is still somewhat up for debate, with experimental evidence for both the E_2u [3] and E_1u [4] representations.
Recent theoretical work has shown that the superconducting state of UPt₃ should exhibit a measurable thermal Hall effect [5], the magnitude of which is proportional to the orbital momentum of the superconducting order parameter. This implies that the thermal Hall coefficient should change when moving between the A and B phases. Furthermore, a sufficiently accurate measurement of the thermal Hall effect may be able to distinguish between the E_2u and E_1u representations.

[1] R. A. Fisher et al. - Phys. Rev. Lett. 62, 1411 (March 1989)
[2] S. Adenwalla et al. - Phys. Rev. Lett. 65, 2298 (October 1990)
[3] J. D. Strand et al. - Science 11 Vol. 328, 5984, pp. 1368-1369 (June 2010)
[4] Y. Machida et al. - Phys. Rev. Lett. 108, 157002 (April 2012)
[5] P. Goswami and A. H. Nevidomskyy - Phys. Rev. B 92, 214504 (December 2015)