engleski

Distinctive Behavior of Superconducting Fluctuations and Pseudogap in Nearly Optimally Doped Single Crystal of HgBa2CuO4+delta

We have applied an unconventional microwave measurement approach to a nearly optimally doped HgBa2CuO4+delta single crystal. The sample geometry assured the total lateral penetration of microwaves due to weak c-axis screening currents. With this cofiguration, one can achieve excellent sensitivity to small changes in conductivity. The data show that the pseudogap opens at T* = 185(15) K, which is almost twice the superconducting critical temperature Tc = 94.3 K. In contrast, the superconducting fluctuation regime is clearly confined to a narrow temperature range Tc < T < T'= 105(2) K, far below T*. This is confirmed by the magnetic-field dependence of the microwave absorption. Hence, our results support the distinction between the physical processes of pseudogap and the superconducting ordering.

superconductivity; microwave; fluctuations; pseudogap

Rad je prezentiran na skupu: 9th International Conference on Materials and Mechanisms of Superconductivity ; održanom od 07.-12.09.2009., Tokii, Japan. ; objavljen u Knjizi sažetaka / Masao Ogata (ur.) ; Tokyo : ICS Convention Design, Inc. , 2009. ; PS-A-31.