Superconductivity of a metallic stripe embedded in an antiferromagnet

Article

关键词: 2-DIMENSIONAL HUBBARD-MODEL;    MONTE-CARLO METHOD;    T-J MODEL;    NEUTRON-SCATTERING;    HARTREE-FOCK;    PHASE-SEPARATION;    HOLES;    SPINS;    LATTICE;    LA2NIO4.125;   

DOI  :  10.1103/PhysRevB.56.8367

来源: SCIE

【 摘 要 】

We study a simple model for the metallic stripes found in La1.6 - xNd0.4SrxCuO4 a two chain Hubbard ladder embedded in a static antiferromagnetic environment. We consider two cases; a ''topological stripe,'' for which the phase of the Neel order parameter shifts by pi across the ladder, and a ''nontopological stripe,'' for which there is no phase shift across the ladder. We perform one-loop renormalization-group calculations to determine the low-energy properties. We compare the results with those of the isolated ladder and show that for small doping superconductivity is enhanced in the topological stripe, and suppressed in the nontopological one. In the topological stripe, the superconducting order parameter is a mixture of a spin-singlet component with zero momentum and a spin-triplet component with momentum pi. We argue that this mixture is generic, and is due to the presence of an additional term in the quantum Ginzburg-Landau action. Some consequences of this mixing are discussed.

【 授权许可】

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