Electronic and structural properties of HgBa₂Ca₂Cu₃O_8+δ, the highest-T_csuperconductor at ambient pressure

The cuprate high-temperature superconductors are extensively studied quantum materials, yet pivotal questions pertaining to the interplay between their structure and electronic properties remain. The mercury-based compounds HgBa₂Ca_n-1Cu_nO_2n+2+δ are notable for their simple tetragonal structures and the highest superconducting transition temperatures, with triple-layer HgBa₂Ca₂Cu₃O_8+δ (n = 3) exhibiting the highest known T_c of 134 K among all superconductors at ambient pressure [1]. However, the growth of sizable high-quality single crystals of these quantum materials, and especially of HgBa₂Ca₂Cu₃O_8+δ, has been a major challenge until recently [2]. Here we present our latest magnetization, charge transport, and diffuse x-ray scattering results and compare our findings to prior work for single-layer HgBa₂CuO_4+δ (n = 1) [3-5] and other cuprates.

[1] A. Schilling et al, Nature 363, 56 (1993)

[2] L. Wang et al., Phys. Rev. Materials 2, 123401 (2018)

[3] D. Pelc et al., Nat. Commun. 10, 2729 (2019)

[4] D. Pelc et al., Phys. Rev. B 102, 075114 (2020)

[5] Z. W. Anderson et al., https://arxiv.org/abs/2405.10411