Fig. 1: Phase diagram.
From: Gapped commensurate antiferromagnetic response in a strongly underdoped model cuprate superconductor
a Phase diagram of Hg1201 (p > 0.04), extended to the undoped insulating state (p = 0) based on data for other cuprates29, with antiferromagnetic (AF), superconducting (SC), pseudogap (PG) and Fermi-liquid (PG + FL) phases/regions. Lines indicate the characteristic pseudogap temperatures T* and T** and superconducting transition temperature Tc obtained from charge transport measurements43, and the approximate Néel temperature TN. Red triangles: temperature TAF below which the response centered at qAF is significantly enhanced (present work and refs. 27,28); purple squares; onset of q = 0 magnetic order from polarized neutron diffraction35,36,37; brown diamonds: onset of nematic order from torque magnetometry59; yellow and orange circles: characteristic temperatures of the onset of short-range charge-density-wave (CDW) order obtained from X-ray29 and optical60 measurements. At the doping level of the present study (p \(\approx\) 0.064, indicated by the arrow), CDW correlations are weak. b Schematic diagrams of magnetic excitation spectra for Hg1201-UD55 (present work), Hg1201-UD7128, and Hg1201-UD8827 at two temperatures (above and below Tc), showing the characteristics of the magnetic dispersion as a function of energy (vertical) and momentum transfer centered at qAF (horizontal). The circle indicates the presence of a resonance in Hg1201-UD88, near optimal doping.
