MAGNETIC FIELD EFFECTS ON T_C AND THE PSEUDOGAP ONSET TEMPERATURE IN CUPRATE SUPERCONDUCTORS

摘要

We study the sensitivity of T_c and the pseudogap onset temperature, T~*, to low fields, H, for cuprate superconductors, using a BCS-based approach extended to arbitrary coupling. We find that T~* and T_c, which are of the same superconducting origin, have very different H dependences. The small coherence length makes T~* rather insensitive to the field. However, the presence of the pseudogap at T_c makes T_c more sensitive to H. Our results for the coherence length ξ fit well with existing experiments. We predict that very near the insulator ξ will rapidly increase.