Pair-density-wave superconductor from doping Haldane chain and rung-singlet ladder

Abstract

We report the numerical discovery of a pair-density-wave (PDW) superconductor from doping either (i) a spin-one Haldane chain or (ii) a two-leg ladder in the rung singlet phase in which the doped charges occupy a single leg. We model these systems using a generalized Kondo model. The itinerant electrons are correlated and described by the $t-J$ model, and are further coupled to a spin $1/2$ Heisenberg model through the Kondo coupling $J_K$. When the density of electrons $x$ is one, the Mott insulator is in a Haldane phase or in a rung singlet phase depending on whether $J_K$ is negative or positive. Upon doping, a pair-density-wave with $\mathbf{Q}=\pi$ can emerge for both signs of $J_K$. In the $J_K\to -\infty$ limit, the model reduces to the recently proposed type II t-J model and we observes a continuous transition between the PDW superconductor and an unconventional Luttinger liquid phase with doping. We also identify a composite order parameter for the superconductor, which can be understood as a Cooper pair formed by two nearby fermionic spin-polarons. Our model and the predicted PDW phase can be experimentally realized by doping S=1 chains formed by Ni${}^{2+}$ in a solid state system or a two-leg ladder of fermionic cold atoms with a potential bias between legs, which preferentially dopes carriers into a single leg.

5+19 pages; 4+16 figures

References in corpus (7)

• Observation of fractional edge excitations in nanographene spin chains
• Exploration of doped quantum magnets with ultracold atoms
• Competing magnetic orders in a bilayer Hubbard model with ultracold atoms
• Pair Density Wave correlations in the Kondo-Heisenberg Model
• Pairing Tendencies in a Two-orbital Hubbard Model in One Dimension
• Topological Pair-Density-Wave Superconducting States
• Hubbard model for spin-1 Haldane chains

Cited by in corpus (13)

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• Pair density wave, unconventional superconductivity, and non-Fermi liquid quantum critical phase in frustrated Kondo lattice
• Luther-Emery liquid and dominant singlet superconductivity in the hole-doped Haldane spin-1 chain
• Terminable Transitions in a Topological Fermionic Ladder
• Strong pair-density-wave fluctuations in an exactly solvable doped Mott insulator
• Lieb-Schultz-Mattis constraints for the insulating phases of the one-dimensional SU($N$) Kondo lattice model
• Numerical signatures of ultra-local criticality in a one dimensional Kondo lattice model
• Instability of the Haldane Phase: Roles of Charge Fluctuations and Hund's Coupling
• Pair-density-wave phase of strongly interacting electrons on the triangular lattice: A variational Monte Carlo study
• Evidence for valence-bond pairing in a one-dimensional two-orbital system
• Spin-triplet pair density wave superconductors