Quasiparticle description of angle-resolved photoemission spectroscopy for SrCuO2

Using a high-fidelity diagrammatic many-body theory we show that ARPES in SrCuO2 can be understood as a one-body effect arising from mild disorder in a long-range antiferromagnetic ground state. the emergence of the so-called spinon branch arises naturally from spin disorder, the anomalous linewidths are accurately captured, and we provide a compelling explanation for the spectral weight observed at the non-magnetic zone boundary. This reinterpretation provides a unified explanation for key experimental signatures previously attributed to spin-charge separation, including features observed in optical conductivity. By comparing the spectral features of SrCuO2 with those of La2CuO4, we argue that SrCuO2 shares notable similarities with the two-dimensional cuprates—both being rooted in a common CuO4 plaquette-based molecular orbital framework.