Paring density waves as the origin of a ring-like rixs profile in bi₂sr₂cacu₂o_8+δ

Density modulations in cuprates are widely believed to be a signature of a charge-density-wave (CDW) order that competes with superconductivity. Recently, we used a weak-coupling approach to claim that these modulations are better accounted by the coexistence of a homogeneous d-wave gap and short-ranged pairing density waves (PDW) [1]. The full momentum dependence of the density waves in Bi₂Sr₂CaCu₂O_8+δ (Bi2212) was recently explored in a resonant inelastic x-ray (RIXS) experiment that spanned the entire copper-oxide plane [2], in contrast to previous studies which showed only one-dimensional cuts along specific directions. The main result of this experiment was an apparent ‘ring’ charge order in all directions of the copper-oxide plane. Here, we show that our approach captures well this ring-like intensity profile and its correspondence energy dependency. These results are compatible with the interpretation that the density modulations in cuprates have a predominant PDW character.