High Temperature Superconductivity in a Lightly Doped Quantum Spin Liquid

Abstract

We have performed density-matrix renormalization group studies of a square lattice t−J model with small hole doping, δ≪1, on long four and six-leg cylinders. We include frustration in the form of a second-neighbor exchange coupling, J2=J1/2, such that the undoped (δ=0) “parent” state is a quantum spin liquid. In contrast to the relatively short range superconducting (SC) correlations that have been observed in recent studies of the six-leg cylinder in the absence of frustration, we find power-law SC correlations with a Luttinger exponent, KSC≈1, consistent with a strongly diverging SC susceptibility, χ∼T−(2−KSC) as the temperature T→0. The spin-spin correlations—as in the undoped state—fall exponentially suggesting that the SC “pairing” correlations evolve smoothly from the insulating parent state.

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