Single-hole spectral function of the t-J-Q model

We study the single-hole spectral function of the t-J-Q model in one- and two-dimensional and two-leg systems by means of stochastic analytic continuation of quantum Monte Carlo imaginary-time data. For one-dimensional systems, we observe the phenomenon of spin-charge separation which persists even deep in the valance bond solid phase with the inclusion of Q₂ and Q₃ terms, which represent interactions in the form of two and three singlet projectors, respectively. In some cases, possible spin-polaron signatures are also observed. For two-leg t-J systems, by gradually increasing the interactions along the rungs, we find the spin-charge separation phenomenon slowly disappears in the bonding band, which corresponds to ky=0, and a spin-polaron starts to form. For the antibonding spectra, which corresponds to ky=π, two distinct bands form and converge at k=(π,π). For two-dimensional t-J-Q systems, we study the possibility of the spin-polaron feature and possible spin-charge separation related to the deconfined quantum critical point.