NMR relaxation rate of O-17 in Sr2CuO2Cl2: Probing two-dimensional magnons at short distances

Article

关键词: QUANTUM HEISENBERG-ANTIFERROMAGNET;    LOW-TEMPERATURES;    DYNAMICS;    LA2CUO4;   

DOI  :  10.1103/PhysRevB.56.3338

来源: SCIE

【 摘 要 】

We calculate the nuclear relaxation rate 1/T-1(O) of oxygen in the undoped quasi-two-dimensional quantum Heisenberg antiferromagnet Sr2CuO2Cl2 above the Neel temperature. The calculation is performed at two-loop order with the help of the Dyson-Maleev formulation of the spin-wave expansion, taking all scattering processes involving two and three magnons into account. At low temperatures T we find 1/T-1(O)=c(1)T(3)+c(2)T(4)+O(T-5), and give explicit expressions for the coefficients c(1) (two-magnon scattering) and c(2) (three-magnon scattering). We compare our result with a recent experiment by Thurber et al. and show that this experiment directly probes the existence of short-wavelength magnons in a two-dimensional antiferromagnet.

【 授权许可】

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