Electronic spectra with paramagnon fractionalization in the single-band Hubbard model

We examine spectral properties of a recently proposed theory of the intermediate temperature pseudogap metal phase of the cuprates. We show that this theory can be obtained from the familiar paramagnon theory of nearly antiferromagnetic metals by fractionalizing the paramagnon into two hidden layers of S = 1/2 spins. The first hidden layer of spins hybridizes with the electrons as in a Kondo lattice heavy Fermi liquid, whereas the second hidden layer of spins forms a spin liquid with fractionalized spinon excitations. We compute the imaginary part of the electronic self-energy induced by the spinon excitations. The energy and momentum dependence of the photoemission spectrum across the Brillouin zone provides a good match to observations by He et al. [Science 331, 1579 (2011)] in (Pb-x, Bi2-x)(LaySr2-y)CuO6+delta and by Chen et al. [Science 366, 1099 (2019)] in (Bi, Pb)(2)Sr2CaCu2O8+delta.

Automated summary

We examined the spectral properties of the intermediate temperature pseudogap metal phase of the cuprates proposed in a recent theory. The theory suggests that this phase can be derived from the paramagnon theory of nearly antiferromagnetic metals by fractionalizing the paramagnon into two hidden layers of S = 1/2 spins. The first hidden layer hybridizes with the electrons, similar to a Kondo lattice heavy Fermi liquid, while the second hidden layer forms a spin liquid with fractionalized spinon excitations. By computing the imaginary part of the electronic self-energy induced by the spinon excitations, we found that the energy and momentum dependence of the photoemission spectrum across the Brillouin zone matches well with experimental observations in (Pb-x, Bi2-x)(LaySr2-y)CuO6+delta and (Bi, Pb)(2)Sr2CaCu2O8+delta samples by He et al. [Science 331, 1579 (2011)] and Chen et al. [Science 366, 1099 (2019)] respectively.