Ground-State Properties of the t-J Model for the CuO Double-Chain Structure

Kurzfassung

We investigate the ground-state properties of a correlated model for the double-chain structure in cuprates. We consider the t-J model, in which the nearest-neighbor spin interaction J1 is smaller than the next-nearest-neighbor interaction J2 corresponding to the CuO double-chain structure. We vary J1 from antiferromagnetic to ferromagnetic values and calculate the correlation functions including the superconducting pair correlation function. Employing the density-matrix renormalization group method, we show that the ground state for antiferromagnetic J1 exhibits the hallmarks of the Luther-Emery liquid phase, in which the spin-singlet pair and charge-density-wave correlations exhibit power-law decays against distance, and the spin correlation function decays exponentially. Its signatures are gradually dismissed as J1 approaches the ferromagnetic regime. Our findings suggest that the antiferromagnetic double-chain structure without ferromagnetic bonds is favorable for superconductivity.