Quasiexcitations and superconductivity in the t-J model on a ladder

Article

关键词: LUTTINGER-LIQUID BEHAVIOR;    CHARGE-SPIN SEPARATION;    2-CHAIN HUBBARD-MODEL;    GAUGE-FIELDS;    HIGH-TEMPERATURE;    SIGMA-MODEL;    DYNAMICS;    PHASE;    CHAINS;   

DOI  :  10.1103/PhysRevB.57.13790

来源: SCIE

【 摘 要 】

We study the t-J model on a ladder using the slave-fermion-CP1 formalism that has been used successfully in studying lightly-doped high-T-c cuprates. We obtain a low-energy effective model assuming a short-range antiferromagnetic order (SRAFO), which includes gauge-field degrees of freedom because of the use of the slave-particle picture. We give a systematic study on the dynamics of composite gauge bosons to show that the confinement phase is realized in a two-leg system whereas the deconfinement phase is realized in a chain system. This explains why quasiexcitations are so different in the chain and ladder systems. The effective model also reveals attractive forces between holes, which generate d-wave-type superconductive correlations in SRAFO. The low-energy excitations on a ladder are consistently described by the universality class of the Lurher-Emery liquid.

【 授权许可】

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