Low-temperature thermal conductivity of the trilayer cuprate Hg1223

The sustained intensity of interest in the high-T_c cuprate superconductors owes much to the rich phenomenology displayed across their phase diagrams; this diversity of phenomena in close proximity is nowhere more apparent than in the multilayer cuprate materials, where the charge imbalance between CuO₂ plane layers has been recently shown to allow the coexistence of competing orders within the same unit cell, hosted by different layers [1-3]: a striking example is the trilayer cuprate Hg1223 (HgBa₂Ca₂Cu₃O_8+δ), for which recent quantum oscillation measurements on samples with p ≈ 8% suggest antiferromagnetic order in the inner plane, surrounded by charge order in the outer planes [3].



The influence of these orders on the coexisting superconductivity remains an important issue, and low-temperature thermal conductivity measurements can be a powerful probe of the relevant low-energy quasiparticles deep in the superconducting state. To this end, we will present new dilution-fridge-temperature thermal conductivity measurements as a function of magnetic field on underdoped Hg1223 (for T_c = 78 K and 112 K) as well as the related single-layer cuprate Hg1201 (HgBa₂CuO_6+δ, for T_c = 74 K), along with comparison to other cuprates.



[1] Ideta et al., Phys. Rev. Lett. 104, 227001 (2010).

[2] Mukuda et al., J. Phys. Soc. Jpn. 81, 011008 (2012).

[3] Oliviero et al., Nat. Commun. 13, 1568 (2022).