Reply to Comment on 'Diamagnetism and Cooper pairing above T-c in cuprates'

Editorial Material

关键词: LAYERED SUPERCONDUCTORS;    FLUCTUATION;    BI2SR2CACU2O8+DELTA;    TRANSITION;    STATE;   

DOI  :  10.1103/PhysRevB.87.056502

来源: SCIE

【 摘 要 】

We analyze recent torque measurements of the magnetization M-d vs magnetic field H in optimally doped YBa2Cu3O7-y (OPT YBCO) to argue against a recent proposal by R. I. Rey et al. [Phys. Rev. B 87, 056501 (2013)] that the magnetization results above T-c are consistent with Gaussian fluctuations. We find that despite its strong interlayer coupling, OPT YBCO displays an anomalous nonmonotonic dependence of M-d on H which represents direct evidence for the locking of the pair wave function phase theta(n) at T-c and the subsequent unlocking by a relatively weak H. These unusual features characterize the unusual nature of the transition to the Meissner state in cuprate superconductors. They are absent in low-T-c superconductors to our knowledge. We also stress the importance of the vortex liquid state, as well as the profiles of the melting field H-m(T) and the upper critical field curve H-c2(T) in the T-H plane. Contrary to the claims of Rey et al., we show that the curves of the magnetization and the Nernst signal illustrate the inaccessibility of the H-c2 line near T-c. The prediction of the H-c2 line by Rey et al. is shown to be invalid in OPT YBCO. DOI: 10.1103/PhysRevB.87.056502

【 授权许可】

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