Magnetic Field Effects in the Pseudogap Phase: A Competing Energy Gap Scenario for Precursor Superconductivity

Abstract

We study the sensitivity of T_c and T^* to low fields, H, within the pseudogap state 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. This is due to the pseudogap, Δ_{pg}, which is present at the latter, but not former temperature. Our results for the coherence length ξfit well with existing experiments.We predict that very near the insulator ξwill rapidly increase.