paper

Metallic and insulating stripes and their relation with superconductivity in the doped Hubbard model

arXiv:1905.02658 · doi:10.21468/SciPostPhys.7.2.021

Abstract

The dualism between superconductivity and charge/spin modulations (the so-called stripes) dominates the phase diagram of many strongly-correlated systems. A prominent example is given by the Hubbard model, where these phases compete and possibly coexist in a wide regime of electron dopings for both weak and strong couplings. Here, we investigate this antagonism within a variational approach that is based upon Jastrow-Slater wave functions, including backflow correlations, which can be treated within a quantum Monte Carlo procedure. We focus on clusters having a ladder geometry with legs (with ranging from to ) and a relatively large number of rungs, thus allowing us a detailed analysis in terms of the stripe length. We find that stripe order with periodicity in the charge and in the spin can be stabilized at doping . Here, there are no sizable superconducting correlations and the ground state has an insulating character. A similar situation, with , appears at . Instead, for smaller values of dopings, stripes can be still stabilized, but they are weakly metallic at and metallic with strong superconducting correlations at , as well as for intermediate (incommensurate) dopings. Remarkably, we observe that spin modulation plays a major role in stripe formation, since it is crucial to obtain a stable striped state upon optimization. The relevance of our calculations for previous density-matrix renormalization group results and for the two-dimensional case is also discussed.

17 pages, 8 figures, submission to SciPost

References in corpus (9)

Cited by in corpus (22)