Annealing Study of the Cuprate Superconductor HgBa2CuO4+δ

Abstract

The discovery of high-temperature superconductivity in cuprates in the 1980s triggered an unprecedented investigation into this exciting family of quantum materials. This work explores the electronic phase diagram of the cuprate HgBa2Cu4+δ (Hg1201). The electronic “hole” concentration of Hg1201 and other cuprates can be adjusted by changing the density of interstitial oxygen atoms. High-quality single crystals of Hg1201 with low hole concentrations are very difficult to produce without destroying samples because harsh annealing environments are required to remove interstitial oxygen. Our goal is to reliably produce Hg1201 crystals with low hole concentrations to allow for subsequent measurement of their structural and electronic properties.