The ghost-Gutzwiller variational wavefunction within the Gutzwiller approximation is shown to stabilize a genuine paramagnetic Mott insulator in the half-filled single-band Hubbard model. This phase hosts quasiparticles that are crucial to the paramagnetic response without showing up in the single-particle spectrum, and, as such, they can be legitimately regarded as an example of Anderson's spinons. We demonstrate that these spinons at the interface with a metal reacquire charge by proximity effect and thus reemerge in the spectrum as a heavy-fermion band.
@article{arxiv.2412.12748,
title = {Revealing spinons by proximity effect},
author = {Antonio Maria Tagliente and Carlos Mejuto-Zaera and Michele Fabrizio},
journal= {arXiv preprint arXiv:2412.12748},
year = {2025}
}