Role of disorder on the quantum critical point of a model for heavy fermions

Article

关键词: ANTIFERROMAGNETIC SPIN-1 CHAIN;    KONDO-LATTICE;    RENORMALIZATION-GROUP;    TRANSVERSE-FIELD;    LIQUID BEHAVIOR;    MONTE-CARLO;    ISING-MODEL;    TRANSITION;    PHASE;    GLASS;   

DOI  :  10.1103/PhysRevB.64.140402

来源: SCIE

【 摘 要 】

A zero-temperature real-space renormalization group (RG) approach is used to investigate the role of disorder near the quantum critical point (QCP) of a Kondo necklace (XY-KN) model. In the pure case this approach yields J(c)=0 implying that any coupling J not equal0 between the local moments and the conduction electrons leads to a nonmagnetic phase. We also consider an anisotropic version of the model (X-KN), for which there is a quantum phase transition at a finite value of the ratio between the coupling and the bandwidth, (J/W). Disorder is introduced either in the on-site interactions or in the hopping terms. We find that in both cases randomness is irrelevant in the X-KN model, i.e., the disorder induced magnetic-nonmagnetic quantum phase transition is controlled by the same exponents of the pure case. Finally, we show the fixed point distributions P-J(J/W) at the attractors of the disordered, nonmagnetic phases.

【 授权许可】

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