2025/04/24 by Altangerel, Munkhtuguldur, Barthélemy, Quentin, Lefrançois, Étienne +12
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2504.17623
The thermal Hall conductivity of the trilayer cuprate HgBa2Ca2Cu3O8+δ (Hg1223) - the superconductor with the highest critical temperature Tc at ambient pressure - was measured at temperatures down to 2 K for three dopings in the underdoped regime (p = 0.09, 0.10, 0.11). By combining a previously introduced simple model and prior theoretical results, we derive a formula for the inverse mean free path, 1 / ℓ, which allows us to estimate the mean free path of d-wave quasiparticles in Hg1223 below Tc. We find that 1 / ℓ grows as T3, in agreement with the theoretical expectation for a clean d-wave superconductor. Measurements were also conducted on the single layer mercury-based cuprate HgBa2CuO6+δ (Hg1201), revealing that the mean free path in this compound is roughly half that of its three-layered counterpart at the same doping (p = 0.10). This observation is be attributed to the protective role of the outer planes in Hg1223, which results in a more pristine inner plane. We also report data in an ultraclean crystal of YBa2Cu3Oy (YBCO) with full oxygen content p = 0.18, believed to be the cleanest of any cuprate, and find that ℓ is not longer than in Hg1223.