Nature of strong hole pairing in doped Mott antiferromagnets

Abstract

Cooper pairing instability in a Fermi liquid is well understood by the BCS theory, but pairing mechanism for doped Mott insulators still remains elusive. Previously it has been shown by density matrix renormalization group (DMRG) method that a single doped hole is always self-localized due to the quantum destructive interference of the phase string signs hidden in the t-J ladders. Here we report a DMRG investigation of hole binding in the same model, where a novel pairing-glue scheme beyond the BCS realm is discovered. Specifically, we show that, in addition to spin pairing due to superexchange interaction, the strong frustration of the phase string signs on the kinetic energy gets effectively removed by pairing the charges, which results in strong binding of two holes. By contrast, if the phase string signs are switched off artificially, the pairing strength diminishes significantly even if the superexchange coupling remains the same. In the latter, unpaired holes behave like coherent quasiparticles with pairing drastically weakened, whose sole origin may be attributed to the resonating-valence-bond (RVB) pairing of spins. Such non-BCS pairing mechanism is therefore beyond the RVB picture and may shed important light on the high-T_c cuprate superconductors.

8+2 pages, 6+4 figures

References in corpus (2)

• On the sign structure of doped Mott insulators
• Universal Behavior and the Two-component Character of Magnetically Underdoped Cuprate Superconductors

Cited by in corpus (34)

• Exploration of doped quantum magnets with ultracold atoms
• Parton theory of magnetic polarons: Mesonic resonances and signatures in dynamics
• Superconductivity in the doped $t$-$J$ model: results for four-leg cylinders
• One hole in the two-leg t-J ladder and adiabatic continuity to the non-interacting limit
• Quasiparticle collapsing in an anisotropic $t$-$J$ ladder
• Pairing versus phase coherence of doped holes in distinct quantum spin backgrounds
• Critical role of the sign structure in the doped Mott insulator: Superconductivity vs. Fermi liquid
• Two-Hole Ground State: Dichotomy in Pairing Symmetry
• Pairing of holes by confining strings in antiferromagnets
• Charge modulation as fingerprints of phase-string triggered interference
• Hidden spin current in doped Mott antiferromagnets
• Intrinsic translational symmetry breaking in a doped Mott insulator
• Breakdown of the Bloch-wave behavior for a single hole in a gapped antiferromagnet
• Two-hole ground state wavefunction: Non-BCS pairing in a $t$-$J$ two-leg ladder system
• Single-hole wave function in two dimensions: A case study of the doped Mott insulator
• Exact sign structure of the $t$-$J$ chain and the single hole ground state
• Localization in a $t$-$J$ type ladder with translational symmetry
• The spectral function of Mott-insulating Hubbard ladders: From fractionalized excitations to coherent quasi-particles
• On the possibility of many-body localization in a doped Mott insulator
• Two holes in a two-dimensional quantum antiferromagnet: A variational study based on entangled-plaquette states
• Superconductivity in doped triangular Mott insulators: the roles of parent spin backgrounds and charge kinetic energy
• Spin and charge modulations in a single hole doped Hubbard ladder -- verification with optical lattice experiments
• Phase Diagram of the Square-Lattice $t$-$J$-$V$ Model for Electron-Doped Cuprates
• Fractional charge and emergent mass hierarchy in diagonal two-leg t-J cylinders
• Strongly enhanced superconductivity in coupled t-J segments
• Spin Texture in Doped Mott Insulators with Spin-Orbit Coupling
• Continuous transition from a Landau quasiparticle to a neutral spinon
• Pairing tendencies in the doped Kitaev-Heisenberg model
• Enhanced superconductivity and various edge modes in modulated $t$-$J$ chains
• Mottness, Phase String, and High-$T_c$ Superconductivity
• Tuning competition between charge order and superconductivity in the square-lattice $t$-$t^{\prime }$-$J$ model
• Complex Phase Diagram of Doped XXZ Ladder: Localization and Pairing
• Spatial structure of magnetic polarons in strongly interacting antiferromagnets
• Possibility of hole confinement in the weak coupling regime of one dimensional ising antiferromagnet and the emergence of spin-charge separation in the bulk limit