Impurities near an antiferromagnetic-singlet quantum critical point

Article

关键词: 2-DIMENSIONAL HUBBARD-MODEL;    NONMAGNETIC IMPURITIES;    ELECTRONIC-STRUCTURE;    SPIN-LIQUID;    ORDER;    SUPERCONDUCTORS;    TRANSITION;    DISORDER;    TEMPERATURES;    PLANE;   

DOI  :  10.1103/PhysRevB.95.054419

来源: SCIE

【 摘 要 】

Heavy-fermion systems and other strongly correlated electron materials often exhibit a competition between antiferromagnetic (AF) and singlet ground states. Using exact quantum Monte Carlo simulations, we examine the effect of impurities in the vicinity of such an AF-singlet quantum critical point (QCP), through an appropriately defined impurity susceptibility chi(imp). Our key finding is a connection within a single calculational framework between AF domains induced on the singlet side of the transition and the behavior of the nuclear magnetic resonance (NMR) relaxation rate 1/T-1. We show that local NMR measurements provide a diagnostic for the location of the QCP, which agrees remarkably well with the vanishing of the AF order parameter and large values of chi(imp).

【 授权许可】

Free