Mean-field description of the phase string effect in the t-J model

Article

关键词: VALENCE-BOND STATE;    SPIN-CHARGE SEPARATION;    DOPED ANTIFERROMAGNET;    QUANTUM ANTIFERROMAGNETS;    HUBBARD-MODEL;    GAUGE-THEORY;    SUPERCONDUCTIVITY;    EXCITATIONS;    FERMION;    RVB;   

DOI  :  10.1103/PhysRevB.59.8943

来源: SCIE

【 摘 要 】

A mean-field treatment of the phase string effect in the t-J model is presented. Such a theory is able to unite the antiferromagnetic (AF) phase at half-filling and the metallic phase at finite doping within a single theoretical framework. We find that the low-temperature occurrence of the AF long-range ordering (AFLRO) at half-filling and superconducting condensation in the metallic phase are all due to Bose condensations of spinons and holons, respectively, on the top of a spin background described by bosonic resonating-valence-bond pairing. The fact that both spinons and holon here are bosonic objects, as the result of the phase string effect, represents a crucial difference from the conventional slave-boson and slave-fermion approaches. This theory also allows an underdoped metallic regime where the Bose condensation of spinons can still exist. Even though the AFLRO is gone here, such a regime corresponds to a microscopic charge inhomogeneity with short-ranged spin ordering. We discuss some characteristic experimental consequences for those different metallic regimes. A perspective on broader issues based on the phase string theory is also discussed. [S0163-1829(99)04213-7].

【 授权许可】

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